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Computer fundamentals

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Computer fundamentals

Computer fundamentalsAll About Computers

Computer fundamentals

Classification of computers

Classification of computers

Mainframe computersA mainframe (also known as "big iron") is a high-performance computer used for large-scale computing purposes that require greater availability and security than a smaller-scale machine can offer. Historically, mainframes have been associated with centralized rather than distributed computing, although that distinction is blurring as smaller computers become more powerful and mainframes become more multi-purpose. Today emphasizes that their mainframes can be used to serve distributed users and smaller servers in a computing network.The original mainframes were housed in room-sized metal frames, which is probably where the name derives from. In the past, a typical mainframe might have occupied 2,000 - 10,000 square feet. Newer mainframes are about the same size as a large refrigerator.

Uses of mainframe computer

E-Business and E-CommerceBoth e-business and e-commerce use mainframe computers to perform business functions and exchange money over the Internet. Banking institutions, stock brokerage firms, insurance agencies and Fortune 500 companies are just a few examples of public and private sectors that maintain information and transfer data via mainframes. Whether a business processes millions of customer orders, performs financial transactions, pays employees or tracks production and inventory, a mainframe computer is the only machine that has the storage, speed and capacity to run successful e-commerce and e-business activities.

Health CareChances are, anytime you go to the doctor, schedule surgery, refill a prescription or inquire about your health insurance benefits, this information is being accessed from a mainframe computer. Mainframe systems also manage patient privacy, as required by Health Insurance Portability and Accountability Act regulations. Doctors can access test results for mammograms, MRIs and electrocardiograms quickly and easily, speeding up patient diagnosis and treatment.

Military useChances are, anytime you go to the doctor, schedule surgery, refill a prescription or inquire about your health insurance benefits, this information is being accessed from a mainframe computer. Mainframe systems also manage patient privacy, as required by Health Insurance Portability and Accountability Act regulations. Doctors can access test results for mammograms, MRIs and electrocardiograms quickly and easily, speeding up patient diagnosis and treatment.

Academics and researchPublic and private libraries, as well as colleges and universities, use mainframe computers for storage of critical data. The Library of Congress, dating back to 1800, offers Congress a plethora of resources through its mainframe databases. American Memory is part of the library's online resource to the public and features access to sound recordings, moving images, prints, maps and documents. Higher academic institutions store student data including grades, transcripts and degree information.

SupercomputersAsupercomputeris acomputerwith a very high-level computational capacity. Performance of a supercomputer is measured infloating pointoperations per second (FLOPS). As of 2015, there are supercomputers which could perform up-to quadrillions of FLOPS.[2]Supercomputers were introduced in the 1960s, made initially, and for decades primarily, bySeymour CrayatControl Data Corporation(CDC),Cray Researchand subsequent companies bearing his name or monogram. While the supercomputers of the 1970s used only a fewprocessors, in the 1990s machines with thousands of processors began to appear and, by the end of the 20th century,massively parallelsupercomputers with tens of thousands of "off-the-shelf" processors were the norm.[3][4]China'sTianhe-2supercomputer is currently thefastest in the worldat 33.86petaFLOPS (PFLOPS), or 33.86 quadrillion floating point operations per second.[2]

Uses of supercomputers

Modeling swine fluPotential pandemics like the H1N1 swine flu require a fast response on two fronts: First, researchers have to figure out how the virus is spreading. Second, they have to find drugs to stop it.Supercomputers can help with both. During the recent H1N1 outbreak, researchers at Virginia Polytechnic Institute and State University in Blacksburg, Va., used an advanced model of disease spread called Epidemics to predict the transmission of the flu. The program, which is designed to model populations up to 300 million strong, was used by the U.S. Department of Defence during the outbreak, according to a May 2009 report in IEEE Spectrum magazine.

Testing nuclear weaponSince 1992, the United States has banned the testing ofnuclear weapons. But that doesn't mean the nuclear arsenal is out of date.The Stockpile Stewardship program uses non-nuclear lab tests and, yes, computer simulations to ensure that the country's cache of nuclear weapons are functional and safe. In 2012, IBM plans to unveil a new supercomputer, Sequoia, at Lawrence Livermore National Laboratory in California. According to IBM, Sequoia will be a 20 pet flop machine, meaning it will be capable of performing twenty thousand trillion calculations each second. Sequoia's prime directive is to create better simulations of nuclear explosions and to do away with real-world nuke testing for good.

Forecasting hurricaneWith Hurricane Ike bearing down on the Gulf Coast in 2008, forecasters turned to Ranger for clues about the storm's path. This supercomputer, with its cowboy moniker and 579 trillion calculations per second processing power, resides at the TACC in Austin, Texas. Using data directly from National Oceanographic and Atmospheric Agency airplanes, Ranger calculated likely paths for the storm. According to a TACC report, Ranger improved the five-day hurricane forecast by 15 percent.Simulations are also useful after a storm. When Hurricane Rita hit Texas in 2005, Los Alamos National Laboratory in New Mexico lent manpower and computer power to model vulnerable electrical lines and power stations, helping officials make decisions about evacuation, power shutoff and repairs.

Predicting weather changesThe challenge of predicting global climate is immense. There are hundreds of variables, from the reflectivity of the earth's surface (high for icy spots, low for dark forests) to the vagaries of ocean currents. Dealing with these variables requires supercomputing capabilities. Computer power is so coveted by climate scientists that the U.S. Department of Energy gives out access to its most powerful machines as a prize.The resulting simulations both map out the past and look into the future. Models of the ancient past can be matched with fossil data to check for reliability, making future predictions stronger. New variables, such as the effect of cloud cover on climate, can be explored. One model, created in 2008 at Brookhaven National Laboratory in New York, mapped the aerosol particles and turbulence of clouds to a resolution of 30 square feet. These maps will have to become much more detailed before researchers truly understand how clouds affect climate over time.

MinicomputerAminicomputer, or colloquiallymini, is a class of smallercomputersthat developed in the mid-1960s and sold for much less than mainframeand mid-size computers fromIBMand its direct competitors. In a 1970 survey, theNew York Timessuggested a consensus definition of a minicomputer as a machine costing less than25,000 USD,with an input-output device such as a teleprompter and at least four thousand words of memory, that is capable of running programs in a higher level language, such asFortranorBASIC.[1]The class formed a distinct group with its own software architectures and operating systems. Minis were designed for control, instrumentation, human interaction, and communication switching as distinct from calculation and record keeping. Many were sold indirectly toOriginal Equipment Manufacturers(OEMs) for final end use application. During the two decade lifetime of the minicomputer class (1965-1985), almost 100 companies formed and only a half dozen remained.[2]

Uses of minicomputer

Process controlMinicomputers were often used in manufacturing for process control. A minicomputer used for process control had two primary functions -- data acquisition and feedback. For example, factories used minicomputers to monitor the manufacturing process. If an element of the process slowed, stopped or accelerated, the computer recognized the change and made necessary adjustments to the system.

Data managementMinicomputers used for data management could acquire data, generate data or store data. For example, the PDP8 computer bought in the early 1970s by the Wesson Memorial Hospital in Springfield, Massachusetts, was used to generate and store radiation treatment plans for patients and as a database of all patient tumors and related information.

Communication portalMinicomputers were also used as communication tools in larger systems, acting as a "portal" between the human operator and a larger, central computer or processor. The user could run operations such as error checking, polling and line buffering through the minicomputer and then use the device to make system adjustments to the central computer or processor.

WorkstationAworkstationis a special computer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to alocal area networkand runmulti-useroperating systems. The termworkstationhas also been used loosely to refer to everything from amainframe computerterminal to a PC connected to anetwork, but the most common form refers to the group of hardware offered by several current and defunct companies such asSun Microsystems,Silicon Graphics,Apollo Computer,DEC,HPandIBMwhich opened the door for the 3D graphics animation revolution of the late 1990s.Workstations offered higher performance than mainstreampersonal computers, especially with respect toCPUandgraphics, memory capacity, and multitasking capability. Workstations were optimized for thevisualizationand manipulation of different types of complex data such as 3D mechanical design, engineering simulation (e.g.computational fluid dynamics), animation and rendering of images, and mathematical plots. Typically, the form factor is that of adesktop computer, consist of a high resolution display, akeyboardand amouseat a minimum, but also offer multiple displays,graphics tablets, 3D mice (devices for manipulating 3D objects and navigating scenes), etc. Workstations were the first segment of the computer market to present advanced accessories and collaboration tools.

Advantages of workstation

Portability and flexibilityThe primary benefit to owning a laptop or tablet is clear: you can bring the machine with you to meetings, conventions or even take it between home and the office to work seamlessly in both locations. Consider whether, if you primarily used a workstation, you would also need a portable computer to make presentations or to work on the road. If so, skipping the workstation and using a laptop exclusively would save you the cost of a second machine.

Ergonomics and peripheralsWhen paired with an ergonomically sound desk and chair, a desktop computer offers a more comfortable working environment than sitting with a laptop on your knees or hunched over a tablet screen for hours. Even if you do choose a portable option, however, you can still work at a desk; most laptops support connecting a regular desktop monitor, keyboard and mouse. Tablets also work with some external input devices, though compatibility varies from product to product.

Hardware specs and customizationIn general, top-of-the-line desktop computers have more power than premium laptops, and laptops usually cost slightly more than desktop PCs of equal power. Choosing a desktop workstation also gives you more freedom to add hardware later, such as a professional-level graphics card for modelling or a sound card for producing high-quality audio. You can buy laptops designed as workstations, but most off-the-shelf laptops do not include these parts or support hardware additions. Tablets also don't allow for hardware modification, but mobile apps are designed with stock tablet specs in mind.

Software supportAs long as you have the necessary hardware specifications, laptops can run the exact same programs as desktop PCs. Very few tablets can use software that was specifically designed for the Windows environment, though. Productivity software on tablets has come a long way, with Microsoft releasing versions of Office programs for mobile devices, but if your job requires industry-specific software, make sure the apps you need exist before deciding to work exclusively from a tablet. For Android and iOS apps, check the Google Play Store or iTunes Preview on the Web (links in Resources). If you're looking into a Windows RT tablet, preview available apps through the Store app on any Windows 8 PC.

Personal computerApersonal computeris a general-purposecomputerwhose size, capabilities and original sale price make it useful for individuals, and is intended to be operated directly by anend-userwith no intervening computer operator. This contrasts with thebatch processingortime-sharingmodels that allowed larger, more expensiveminicomputerandmainframesystems to be used by many people, usually at the same time. A related term is "PC" that was initially an acronym for "personal computer", but later became used primarily to refer to the ubiquitousWintel platform.Software applications for most personal computers include, but are not limited to,word processing,spreadsheets,databases,web browsersande-mailclients,digital mediaplayback,gamesand myriad personal productivity and special-purpose software applications. Modern personal computers often have connections to theInternet, allowing access to theWorld Wide Weband a wide range of other resources. Personal computers may be connected to alocal area network(LAN), either by a cable or a wireless connection. A personal computer may be adesktop computeror alaptop,net book,tabletor ahandheld PC.

Uses of personal computer

WorkIt is rare these days to find an office that does not have a personal computer. Many work-related activities can be executed in a much better way by using a computer. Employees use office computers for making presentations, creating drafts, keeping records of the company and making spreadsheets. A number of professions these days are directly related to computer usage, including web page and graphic design. With the majority of the world connected to the Internet, individuals can work from their personal computers at home and make their living this way, like website content writers. Personal computers are used for off-line work too. Music studios often use personal computers to record musical tracks. After recording, the tracks can then be mixed and mastered, all on a personal computer.

EducationThe role of the personal computer in the field of education is also prominent . In 2010, it is common among college and school students to have a personal computer at home, and some even bring laptops to school. Students can research papers and essays online, looking for both historical facts and the latest happenings around the globe. Most colleges and schools have personalized web pages to display important notices to students, and students find this to be a convenient way to get updates on campus events. Small children have access to websites for learning to read, learning math, science and many other subjects. Parents can even home-school their children through online curriculum.

GamingComputer gaming has increased in popularity over time. Personal computers can be loaded with components that take the gaming experience of a user to new levels. Desktops need to have high-end graphics cards, processors and lots of RAM for a good gaming experience. Video games can be used on most personal computers, as long as some basic specifications are met. Usually games have to be installed by a CD or downloaded from the Internet. A wide variety of PC games are available to suit different tastes.

Types of personal computer

Tower modelRefers to acomputerin which thepower supply,motherboard, andmass storagedevicesare stacked on top of each other in a cabinet. This is in contrast todesktop models, in which these components are housed in a more compact box. The main advantage of tower models is that there are fewer space constraints, which makes installation of additionalstoragedevices easier.

Desktop modelAcomputerdesigned to fit comfortably on top of a desk, typically with themonitorsitting on top of the computer. Desktop model computers are broad and low, whereastower model computers are narrow and tall. Because of their shape, desktop model computers are generally limited to three internalmass storagedevices. Desktop models designed to be very small are sometimes referred to asslim line models.

Notebook computerAn extremely lightweightpersonal computer. Notebook computerstypically weigh less than 6 pounds and are small enough to fit easily in a briefcase. Aside from size andportability, the principal difference between a notebook computer and a personal computer is thedisplay screen. Notebook computers use a variety of techniques, known asflat-panel technologies, to produce a lightweight and non-bulky display screen.

Laptop computerAlaptopor anotebookis a portablepersonal computerwith aclamshellform factor, suitable formobile use.[1]There was a difference betweenlaptopsandnotebooksin the past, but nowadays it has gradually died away.[2]Laptops are commonly used in a variety of settings, including at work, in education, and for personal multimedia.

Subnotebook computerAportable computerthat is slightly lighter and smaller than a full-sizednotebook computer. Typically, subnotebook computers have a smallerkeyboardandscreen, but are otherwise equivalent to notebook computers.

PalmtopAPalmtop PCwas an aboutpocket calculator-sized, battery-poweredPCin a horizontal clamshell design with integrated keyboard and display. It could be used like a subnotebook, but was light enough to be comfortably used handheld as well. Most Palmtop PCs were small enough to be stored in a user's shirt or jacket pocket.Palmtop PCs distinguish from otherpalmtop computersby utilizing a mostlyIBM-compatiblePC architectureandBIOSas well as an Intel-compatiblex86processor. Most such devices wereDOS-based, with DOS stored inROM.

PDAApersonal digital assistant(PDA), also known as ahandheld PC, orpersonal data assistant,[1][2]is amobile devicethat functions as apersonal information manager. The term evolved from Personal Desktop Assistant, a software term for an application that prompts or prods the user of a computer with suggestions or provides quick reference to contacts and other lists. PDAs were largely discontinued in the early 2010s after the widespread adoption of highly capable, in particulariOSandAndroid-based,smart phones.[3]

Computer languages

Computer Languages

Low-Level LanguagesLow-level languages are machine languages or close to them. A computer cannot understand instructions written in highlevel languages or English. It can only be understand and execute instructions given in the form of machine language, i.e. language of 0 and 1.

Types of Low-Level Language

Machine LanguageIt is the lowest and most elementary level of Programming language and was the first type of programming language to be Developed. Machine Language is basically the only language which computer Can understand. In fact, a manufacturer designs a computer to obey just one Language, its machine code, which is represented inside the computer by a String of binary digits (bits) 0 and 1. The symbol 0 stands for the absence of Electric pulse and 1 for the presence of an electric pulse . Since a computer is Capable of recognizing electric signals, therefore, it understand machine Language.

Advantages and Disadvantages of Machine LanguageAdvantagesIt makes fast and efficient use of the computer. It requires no translator to translate the code i.e. Directly understood by the computer.DisadvantagesAll operation codes have to be rememberedAll memory addresses have to be remembered.It is hard to amend or find errors in a program writtenIn the machine languageThese languages are machine dependent i.e. a particularMachine language can be used on only one type of computer

Assembly LanguageIt was developed to overcome some of the many inconveniences of machine language. This is another low level but a very important language in which operation codes and operands are given in the form of alphanumeric symbols instead of 0s and ls. These alphanumeric symbols will be known as mnemonic codes and can have maximum up to 5 letter combination e.g. ADD for addition, SUB for subtraction, START,LABEL etc. Because of this feature it is also known as Symbolic Programming Language. This language is also very difficult and needs a lot of practice to master it because very smallEnglish support is given to this language. The language mainly helps in compiler orientations. The instructions of the Assembly language will also be converted to machine codes by language translator to be executed by the computer.

Advantages and Disadvantages of Assembly languageAdvantagesIt is easier to understand and use as compared to machine language.It is easy to locate and correct errors.It is modified easily.DisadvantagesLike machine language it is also machine dependent.Since it is machine dependent therefore programmer Should have the knowledge of the hardware also.

High-Level LanguagesHigh level computer languages give formats close to English language and the purpose of developing high level languages is to enable people to write programs easily and in their own native language environment (English). High-level languages are basically symbolic languages that use English words and/or mathematical symbols rather than mnemonic codes. Each instruction in the high level language is translated into many machine language instructions thus showing one-to-many translation.

Types of High-Level Languages

Algebraic Formula-Type ProcessingThese languages are oriented towards the computational procedures for solving mathematical and statistical problemExamples areBASIC (Beginners All Purpose Symbolic Instruction Code).FORTRAN (Formula Translation).PL/I (Programming Language, Version 1).ALGOL (Algorithmic Language).APL (A Programming Language).

Business Data ProcessingThese languages emphasize their capabilities for maintaining data processing procedures and files handling problems. Examples are:COBOL (Common Business Oriented Language). RPG (Report Program Generator

String and List ProcessingThese are used for string manipulation including search for patterns, inserting and deleting characters. Examples are:LISP (List Processing).Prolog (Program in Logic).

Object Oriented Programming LanguageIn OOP, the computer program is divided into objects. Examples are:C++Java

Advantages and disadvantages of High-Level LanguageAdvantagesUser-friendlySimilar to English with vocabulary of words and symbolsTherefore it is easier to learn.They require less time to write.They are easier to maintain.Problem oriented rather than 'machine' based.Program written in a high-level language can be translated into many machine language and therefore can run on any computer for which there exists an appropriate translator.It is independent of the machine on which it is used i.e. Programs developed in high level language can be run on any ComputerDisadvantagesA high-level language has to be translated into the machine language by a translator and thus a price in computer time is paid.The object code generated by a translator might be inefficient Compared to an equivalent assembly language program

Binary Number System

Binary Number SystemTheBinary Numbering Systemis the most fundamental numbering system in all digital and computer based systems and binary numbers follow the same set of rules as the decimal numbering system. But unlike the decimal system which uses powers of ten, the binary numbering system works on powers of two giving a binary to decimal conversion from base-2 to base-10.Digital logic and computer systems use just two values or states to represent a condition, a logic level 1 or a logic level 0, and each 0 and 1 is considered to be a single digit in a Base-of-2 (bi) or binary numbering system.In the binary numbering system, a binary number such as101100101is expressed with a string of 1s and 0s with each digit along the string from right to left having a value twice that of the previous digit. But as it is a binary digit it can only have a value of either 1 or 0 therefore,qis equal to 2 (0 or 1) with its position indicating its weight within the string.As the decimal number is a weighted number, converting from decimal to binary (base 10 to base 2) will also produce a weighted binary number with the right-hand most bit being theLeast Significant BitorLSB, and the left-hand most bit being theMost Significant BitorMSB,

Conversion Binary and Decimal number systemDecimal to Binary ConversionThis is quite simple it can be understand clearly if we follow the example. Let, a decimal number be (87)10. We divide 87 by 2 and get 43 as the quotient and 1 as the remainder. These remainders are written beside as shown below. 287 1243 1221 1210 025 122 01 The possibility of remainder (87)10 = (1010111)2 is only 1 and 0. Thus the number is counted from the last remainder. Such as 1 0 1 0 1 1 1. This is how decimal to binary conversion is doneBinary to Decimal ConversionThis conversion is also very simple method . Let, a binary number be (11010)2 ,Where the weight of the binary digits from M.S.B. are 24, 23,22,21, 20 respectively . Now the bits are multiplied with their weights and the sum of those products is the respective decimal number. Now let us follow the following steps mathematically.(11010)2 1 X 24 + 1 X 23 + 0 X 22 + 1 X 21 + 0 X 20 = 16 + 8 + 2 = (26)10 (11010)2 = (26)10Hence (26)10 is the required decimal number. This is how binary to decimal conversion is done


Computer software

Computer softwareComputer softwareor simplysoftwareis any set of machine-readable instructions that directs acomputer's processor to perform specific operations. Computer software contrasts withcomputer hardware, which is the physical component of computers. Computer hardware and software require each other and neither can be realistically used without the other. Using a musical analogy, hardware is like a musical instrument and software is like the notes played on that instrument.

Types of Computer Software

System SoftwareThe system software is collection of programs designed to operate, control, and extend the processing capabilities of the computer itself. System software are generally prepared by computer manufactures. These software products comprise of programs written in low-level languages which interact with the hardware at a very basic level. System software serves as the interface between hardware and the end users.Some examples of system software are Operating System, Compilers, Interpreter, Assemblers etc.

Types of System Software

Operating SystemAnoperating system(OS) is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system. Without an operating system, a user cannot run an application program on their computer (unless the application program is self booting).Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting for cost allocation of processor time, mass storage, printing, and other resources.For hardware functions such as input/output and main memory management, the operating system acts as a middleman between application programs and the computer hardware, although the application code is usually executed directly by the hardware it will frequently call the OS or be interrupted by it. Operating systems can be found on almost any device that contains a computer, from mobile phones and video game consoles to supercomputers and web servers.Examples of popular modern operating systems include Android, iOS, Linux, Mac OS X and Microsoft Windows, but don't use these names in the exam!

Utility SoftwareUtility softwareis a type of system software which has a very specific task to perform related to the working of the computer, for example anti virus software, disk defragment etc.Utility software should not be confused with application software, which allows users to do things like creating text documents, playing games, listening to music or surfing the web. Rather than providing these kinds of user-oriented or output-oriented functionality, utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates. Due to this focus, utilities are often rather technical and targeted at people with an advanced level of computer knowledge.

Library ProgramLibrary programsare collections compiled routines which are shared by multiple programs, such as the printing function.Illustration of an application which uses libvorbisfile to play anOgg Vorbismedia fileLibrary programs contain code and data that provide services to other programs such as interface (look and feel), printing, network code and even the graphic engines of computer games. If you have ever wondered why all Microsoft Office programs have the same look and feel, that is because they are using the same graphical user interface libraries. For computer games a developer might not have the time and budget to write a new graphics engine so they often buy graphical libraries to speed up development, this will allow them to quickly develop a good looking game that runs on the desired hardware. For example Battlefield 3 and Need for Speed both use the sameFrostbiteengine.The history of game engine developmentMost programming languages have a standard set of libraries that can be used, offering code to handle input/output, graphics and specialist maths functions. You can also create your own custom libraries and when you start to write lots of programs with similar functionality you'll find them very useful.

Translator SoftwareThe final type of system software that you need to know is translator software. This is software that allows new programs to be written and run on computers, by converting source code into machine code. There are three types that we'll cover in a lot more detail shortly:Assembler - converts assembly code into machine codeInterpreter - converts 3rd generation languages such as javascript into machine code one line at a timeCompiler - converts 3rd generation languages such as C++ into machine code all at once

Application SoftwareApplication software products are designed to satisfy a particular need of a particular environment. All software applications prepared in the computer lab can come under the category of Application software.Application software may consist of a single program, such as a Microsoft's notepad for writing and editing simple text. It may also consist of a collection of programs, often called a software package, which work together to accomplish a task, such as a spreadsheet package.

Types of Application Software

Word Processing SoftwareAword processoris an electronic device orcomputersoftware application, that performs the task of composition, editing, formatting, and sometimes printing of documents.The word processor was a stand-alone office machine in the 1960s, combining the keyboard text-entry and printing functions of anelectric typewriter, with a recording unit, either tape orfloppy disk(as used by theWangmachine) with a simple dedicated computer processor for the editing of text.[1]Although features and designs varied among manufacturers and models, and new features were added as technology advanced, word processors typically featured amonochrome displayand the ability to save documents onmemory cardsordiskettes. Later models introduced innovations such asspell-checkingprograms, and improved formatting options.

Spreadsheet SoftwareAspreadsheetis an interactivecomputer applicationprogram for organization, analysis and storage ofdataintabularform. Spreadsheets developed as computerized simulations of paper accountingworksheets. The program operates on data represented as cells of an array, organized in rows and columns. Each cell of the array is amodelviewcontrollerelement that may contain either numeric or text data, or the results offormulasthat automatically calculate and display a value based on the contents of other cells.Spreadsheet users may adjust any stored value and observe the effects on calculated values. This makes the spreadsheet useful for "what-if" analysis since many cases can be rapidly investigated without manual recalculation. Modern spreadsheet software can have multiple interacting sheets, and can display data either as text and numerals, or in graphical form.

Database SoftwareDatabase software is the phrase used to describe anysoftwarethat is designed for creatingdatabasesand managing the information stored in them. Sometimes referred to asdatabase management systems(DBMS), database software tools are primarily used for storing, modifying, extracting, and searching for information within a database. Database software is used for a number of reasons in any industry - from keeping your bookkeeping on task, compiling client lists to running your online Web site.

Presentation Graphic SoftwareApresentation programis asoftwarepackage used to display information in the form of aslide show. It has three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images, and a slide-show system to display the content.[1]