Understanding Essential Computer Concepts. 2 Investigate types of computersInvestigate types of computers Examine computer systemsExamine computer systems

Understanding Essential Computer Concepts

2

• Investigate types of computersInvestigate types of computers

• Examine computer systemsExamine computer systems

• Examine input devicesExamine input devices

• Examine output devicesExamine output devices

• Investigate data processingInvestigate data processing

• Understand memoryUnderstand memory

ObjectivesObjectives

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• Understand storage mediaUnderstand storage media

• Explore data communicationsExplore data communications

• Learn about networksLearn about networks

• Learn about security threatsLearn about security threats

• Understand system softwareUnderstand system software

• Understand application softwareUnderstand application software

ObjectivesObjectives

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Defining ComputersDefining Computers

A A computercomputer is an electronic device is an electronic device that:that:

• accepts inputaccepts input

• processes dataprocesses data

• stores datastores data

• produces outputproduces output

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Investigating Types of Investigating Types of ComputersComputersThe categories of computers are:The categories of computers are:

• Personal computersPersonal computers• DesktopDesktop• Notebook (Laptop) Notebook (Laptop) • Tablet PCTablet PC

• Hand-heldsHand-helds• PDAsPDAs• MP3 playersMP3 players• Cell phonesCell phones

• MainframesMainframes• SupercomputersSupercomputers

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Investigating Types of Investigating Types of ComputersComputers

PersonalPersonal computerscomputers are used for general computing tasks. are used for general computing tasks.

Hand-heldHand-held computerscomputers fit in the palm of your hand and run fit in the palm of your hand and run

on batteries.on batteries.

MainframesMainframes are used by companies to provide centralized are used by companies to provide centralized

storage, processing, and management for large amounts of storage, processing, and management for large amounts of

data.data.

SupercomputersSupercomputers are the largest and fastest of computers, are the largest and fastest of computers,

and can process an enormous volume of data.and can process an enormous volume of data.

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Investigating Types of ComputersInvestigating Types of Computers

• Notebook Notebook computercomputer• also referred to also referred to

as a laptop as a laptop computercomputer

• smallsmall• lightweightlightweight• portableportable

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Investigating Types of ComputersInvestigating Types of Computers

SupercomputersSupercomputers are the largest and fastest of are the largest and fastest of

computers, and can process an enormous computers, and can process an enormous

volume of data.volume of data.

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Examining Computer SystemsExamining Computer Systems

A A computer systemcomputer system is made up of: is made up of:

• HardwareHardware—the physical components—the physical components

• SoftwareSoftware—the programs or lists of —the programs or lists of instructionsinstructions

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• ArchitectureArchitecture or or configurationconfiguration is the is the design of the computer.design of the computer.• As in, what does the computer consist As in, what does the computer consist

of?of?

• SpecificationsSpecifications are the technical details are the technical details about each component.about each component.• As in, how big is the monitor?As in, how big is the monitor?

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• Data

• The words, numbers, figures, sounds, and graphics that describe people, events, things, and ideas

• Processing

• Modifying data

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• MotherboardMotherboard• where processing

tasks occur • located inside the

computer • the main electronic

component of the computer

• contains the CPU

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• The data you type into the computer is called The data you type into the computer is called inputinput..

• The result of the computer processing your The result of the computer processing your input is called input is called outputoutput..

• Peripheral devicesPeripheral devices accomplish the input, accomplish the input, output, and storage functions.output, and storage functions.

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• MicroprocessorMicroprocessor • a silicon chip a silicon chip

designed to designed to manipulate datamanipulate data

• its speed is its speed is determined by:determined by:

• Clock speedClock speed• Word sizeWord size• Processor typeProcessor type

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Examining Input DevicesExamining Input Devices

Some input devices are:Some input devices are:

• KeyboardKeyboard• MouseMouse• TrackballTrackball• Touch padTouch pad• Pointing stickPointing stick• TouchscreenTouchscreen• ScannerScanner• MicrophonesMicrophones

Cordless mouseCordless mouse

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Using Assistive DevicesUsing Assistive Devices

• People who cannot use their arms or hands instead can use foot, head, or eye movements to control the pointer.

• People with poor vision can use keyboards with large keys for input, screen enlargers to enlarge the type and images on the monitor, or screen readers to read the content of the screen aloud.

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Examining Output DevicesExamining Output Devices

• MonitorsMonitors and and printersprinters are common output devices. are common output devices.

• The The monitormonitor displays the output from a computer. displays the output from a computer. Most flat panel monitors use Most flat panel monitors use LCD LCD (liquid crystal (liquid crystal display) technology which creates the image you see display) technology which creates the image you see on the screen by manipulating light within a layer of on the screen by manipulating light within a layer of liquid crystal.liquid crystal.

• A A printerprinter produces a paper copy, often called a hard produces a paper copy, often called a hard copy, of the text processed by the computer.copy, of the text processed by the computer.

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Examining Output Examining Output DevicesDevices

Factors that influence Factors that influence

a monitor’s quality a monitor’s quality are:are:

• Screen SizeScreen Size

• ResolutionResolution

• Dot PitchDot Pitch

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Examining Output DevicesExamining Output Devices

Types of printersTypes of printers• LaserLaser• Dot MatrixDot Matrix• InkjetInkjet

InkjetInkjet printerprinter

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Investigating Data ProcessingInvestigating Data Processing

• A computer file is a named collection of stored data.

• An executable file contains the instructions that tell a computer how to perform a specific task; for instance, the files that are used while the computer starts are executable.

• A data file is created by a user, usually with software.

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• Computers interpret every signal as Computers interpret every signal as “on” or “off.”“on” or “off.”

• 1 (“on”) and 0 (“off”) are referred to as 1 (“on”) and 0 (“off”) are referred to as bitsbits..

• Eight bits is a Eight bits is a bytebyte. Each byte . Each byte represents a unique character.represents a unique character.

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• KilobyteKilobyte ( (KBKB) = one thousand ) = one thousand bytesbytes

• MegabyteMegabyte ( (MBMB) = one million bytes) = one million bytes

• GigabyteGigabyte ( (GBGB) = one billion bytes) = one billion bytes

• TerabyteTerabyte ( (TBTB) = one trillion bytes) = one trillion bytes

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• Each ASCII number represents an English character

• Computers that run the Windows operating system use the set of Extended ASCII definitions defined by the American National Standards Institute (ANSI).

ANSI standard sample ASCII codeANSI standard sample ASCII code

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Understanding MemoryUnderstanding Memory

• Computer Computer memorymemory is a set of storage is a set of storage locations on the motherboard.locations on the motherboard.

• There are five types of memory:There are five types of memory:• Random access memory (RAM)Random access memory (RAM)• Cache memoryCache memory• Virtual memoryVirtual memory• Read-only memoryRead-only memory• Complementary metal oxide Complementary metal oxide

semiconductor memory (CMOS)semiconductor memory (CMOS)

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• RAMRAM • Temporary memory that is constantly Temporary memory that is constantly

changing while the computer is on.changing while the computer is on.• Also called Also called volatile memory volatile memory and and temporary temporary

memorymemory..• Cache memoryCache memory

• Special high-speed memory chip on the Special high-speed memory chip on the motherboard or CPU motherboard or CPU

• Stores frequently and recently accessed Stores frequently and recently accessed data and commands.data and commands.

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• Virtual memoryVirtual memory is extra memory that is extra memory that simulates RAM if more is needed.simulates RAM if more is needed.

• Read-only memory (ROM)Read-only memory (ROM) is the permanent is the permanent storage location for a set of instructions the storage location for a set of instructions the computer uses.computer uses.

• CMOSCMOS memory is semi-permanent memory is semi-permanent information about where essential software is information about where essential software is stored.stored.

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Understanding Storage MediaUnderstanding Storage Media

• Magnetic storage media• Store data as magnetized particles on a

surface.• A hard disk, also called a hard disk drive,

is the most common type of magnetic storage media. It contains several magnetic oxide covered metal platters that are usually sealed in a case inside the computer.

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• Optical storage devices• polycarbonate discs coated with a

reflective metal on which data is recorded using laser technology as a trail of tiny pits or dark spots in the surface of the disc

• the data that these pits or spots represent can then be “read” with a beam of laser light

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• Types of optical storage devicesTypes of optical storage devices

• CD—can store 700 MB of dataCD—can store 700 MB of data

• DVD—can store between 4.7 and DVD—can store between 4.7 and 15.9 GB of data15.9 GB of data

• Blu-ray discs and HD-DVD can store Blu-ray discs and HD-DVD can store between 15 and 50 GB of databetween 15 and 50 GB of data

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• Flash memory—similar to ROM except that it can be written to more than once.

• Flash memory cards• small, portable cards encased in hard

plastic to which data can be written and rewritten

• used in digital cameras, handheld computers, video game controllers, and other devices

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• USB flash storage device (USB drive, flash drive)

• popular type of flash memory

• available in a wide range of sizes from 1 to 64 GB

• plug directly into the USB port of a personal computer

• are about the size of a pack of gum and often have a ring that you can attach to your key chain.

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Erasing and Rewriting on Erasing and Rewriting on CDs and DVDsCDs and DVDs

• CD-ROMCD-ROMs are for “read-only” access.s are for “read-only” access.

• CD-RCD-R drives allow you to record data on a drives allow you to record data on a CD-R disk.CD-R disk.

• CD-RWCD-RW drives allow you to write data on a drives allow you to write data on a CD-RW disk and access and modify data.CD-RW disk and access and modify data.

• DVD-RDVD-R and and DVD+RDVD+R are recordable. are recordable.

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Exploring Data CommunicationsExploring Data Communications

Data communicationsData communications is the transmission of text, is the transmission of text, numeric, voice, or video data from one computer to numeric, voice, or video data from one computer to another.another.

The four essential components of data communications The four essential components of data communications are:are:• SenderSender• ChannelChannel• ReceiverReceiver• ProtocolsProtocols

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• A A sendersender is the computer that originates the is the computer that originates the message.message.

• The The messagemessage is sent over a channel, such as a is sent over a channel, such as a telephone or coaxial cable.telephone or coaxial cable.

• The The receiverreceiver is the computer at the message’s is the computer at the message’s destination.destination.

• ProtocolsProtocols are the rules that establish the are the rules that establish the transfer of data between sender and receiver.transfer of data between sender and receiver.

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• Device driver (or simply driver) • handles the transmission protocol between a

computer and its peripheral devices • a computer program that can establish

communication because it contains information about the characteristics of your computer and of the device

• Data bus • the data path between the microprocessor,

RAM, and the peripherals along which communication travels

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Components needed to connect a printer to a computerComponents needed to connect a printer to a computer

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• An external peripheral device must have a An external peripheral device must have a corresponding expansion port and cable corresponding expansion port and cable that connect it to the computer.that connect it to the computer.

• Inside the computer, each port connects to Inside the computer, each port connects to a controller card, sometimes called an a controller card, sometimes called an expansion card expansion card or or interface cardinterface card. These . These cards plug into electrical connectors on the cards plug into electrical connectors on the motherboard called motherboard called expansion slots expansion slots or or slotsslots..


Types of Personal Computer Ports:Types of Personal Computer Ports:• ParallelParallel• SerialSerial• SCSISCSI• USBUSB• MIDIMIDI• EthernetEthernet

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Exploring Data CommunicationsExploring Data Communications• Parallel port—Parallel port—transmits data eight bits at a transmits data eight bits at a

timetime• Serial portSerial port—transmits data one bit at a time—transmits data one bit at a time• SCSI SCSI (small computer system interface,

pronounced “scuzzy”) port—port—provides an provides an interface for one or more peripheral devices interface for one or more peripheral devices at the same portat the same port

• USB USB (Universal Serial Bus) port—port—a high-a high-speed serial port which allows multiple speed serial port which allows multiple connections at the same portconnections at the same port

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• Sound card port—usually includes jacks Sound card port—usually includes jacks for speakers and a microphone, which are for speakers and a microphone, which are designed to work with a designed to work with a MIDI MIDI ((Musical Musical Instrument Digital InterfaceInstrument Digital Interface, pronounced , pronounced “middy”) “middy”) cardcard

• Ethernet port—Ethernet port—used to connect to used to connect to another computer, a LAN, a modem, or another computer, a LAN, a modem, or sometimes directly to the Internet; allows sometimes directly to the Internet; allows data to be transmitted at high speeds.data to be transmitted at high speeds.

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Exploring Data Exploring Data CommunicationsCommunications

Computer ports and connectionsComputer ports and connections

Power connection

Mouse port

FireWire port

Network port

Phone line connection

Speaker and microphone connections

USB ports

Monitor port

Audio connection

Keyboard port

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Learning about NetworksLearning about Networks

• NetworkNetwork • connects one computer to other computers and connects one computer to other computers and

peripheral devicesperipheral devices• Network interface cardNetwork interface card ( (NICNIC) )

• creates a communications channel between the creates a communications channel between the computer and the networkcomputer and the network

• a cable connects the NIC port to the networka cable connects the NIC port to the network• Network softwareNetwork software

• establishes the communications protocols that will establishes the communications protocols that will be observed on the networkbe observed on the network

• controls the traffic flow of data traveling through controls the traffic flow of data traveling through the networkthe network

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• ServerServer• acts as the central storage location for programs • provides mass storage for most of the data used on the

network

• ClientClient—computers on a network dependent on a —computers on a network dependent on a serverserver

• Client/server networkClient/server network—a network with server that —a network with server that acts as the central storage locationacts as the central storage location

• Peer-to-peer networkPeer-to-peer network• a network without a server a network without a server • all of the computers are equalall of the computers are equal

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• Standalone computerStandalone computer—a—a personal computer that is not connected to a network

• WorkstationWorkstation—a—a personal computer that is connected to a network

• NodeNode—any device connected to the —any device connected to the networknetwork

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Network configurationNetwork configuration

Workstation

Workstation

Your local workstation

Server Printer

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• LANLAN ( (local area networklocal area network))• computers and peripherals located close to each computers and peripherals located close to each

otherother• WAN WAN ((wide area networkwide area network))

• more than one LAN connected together• the Internet is the largest example of a WAN

• WLAN WLAN ((wireless local area networkwireless local area network))• computers and peripherals that use high-

frequency radio waves instead of wires to communicate and connect in a network

• Wi-Fi (wireless fidelity) describes WLANs connected using a standard radio frequency established by the Institute of Electrical and Electronics Engineers (IEEE)

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• PAN PAN ((personal area networkpersonal area network)—)—a network that allows two or more devices located close to each other to communicate or to connect a device to the Internet

• infrared technologyinfrared technology——uses infrared light waves to beam data from one device to another

• BluetoothBluetooth——uses short range radio waves to connect a device wirelessly to another device or to the Internet

• WiMAX WiMAX (Worldwide Interoperability for Microwave Access)

• allows computers to connect over many miles to a LAN

• a WiMAX tower sends signals to a WiMAX receiver built or plugged into a computer

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Using modems to send and receive dataUsing modems to send and receive data

Sending site

Digital signal

Modem

Analog signal

Modem

Digital signal

Receiving site

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Learning about Security ThreatsLearning about Security Threats

• Security

• refers to the steps a computer owner takes to prevent unauthorized use of or damage to the computer

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• Malware• describes any program that is intended to

cause harm or convey information to others without the owner’s permission

• Viruses • harmful programs that instruct your computer

to perform destructive activities, such as erasing a disk drive

• Antivirus software (virus protection software) searches executable files for the sequences of characters that may cause harm and disinfects the files by erasing or disabling those commands

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• Spyware • programs contained with other programs that track a

computer user’s Internet usage and send this data back to the company or person that created it

• usually installed without the computer user’s permission or knowledge

• Anti-spyware software detects spyware and deletes them

• Adware • software installed with another program usually with the

user’s permission• generates advertising revenue for the program’s creator

by displaying targeted ads to the program’s user

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• Firewall • prevents other computers on the Internet from

accessing a computer and prevents programs on a computer from accessing the Internet without the computer user’s permission

• can be either hardware or software• router

• a device that controls traffic between network components

• usually has a built-in firewall.

• software firewalls track all incoming and outgoing traffic

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Learning about Security ThreatsLearning about Security Threats• Spoofed site

• a Web site set up to look like another Web site, but which does not belong to the organization portrayed in the site

• the URL (address on the Web) looks similar to a URL from the legitimate site

• usually set up to try to convince customers of the real site to enter personal information

• Phishing • the practice of sending e-mails to customers or potential

customers of a legitimate Web site asking them to click a link in the e-mail

• the link leads to a spoofed site• Pharming

• when a criminal breaks into a DNS server (a computer responsible for directing Internet traffic) and redirect any attempts to access a particular Web site to the criminal’s spoofed site

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Protecting Information with Protecting Information with PasswordsPasswords• Logging inLogging in

• signing in with a user name and signing in with a user name and passwordpassword

• Strong passwordStrong password• at least eight charactersat least eight characters• consists of upper- and lowercase letters consists of upper- and lowercase letters

and numbersand numbers• does not include common personal does not include common personal

informationinformation

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Understanding System SoftwareUnderstanding System Software

System softwareSystem software helps the computer carry out it s helps the computer carry out it s basic operating tasks.basic operating tasks.

The four types of system software are:The four types of system software are:• Operating systemsOperating systems• UtilitiesUtilities• Device driversDevice drivers• Programming languagesProgramming languages

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• OperatingOperating systemsystem• controls the controls the input input and and outputoutput ( (I/OI/O))• allocates system resourcesallocates system resources• manages files on storage devicesmanages files on storage devices• guards against equipment failureguards against equipment failure

• Operating environmentOperating environment• provides a provides a graphical user interfacegraphical user interface ( (GUIGUI) )

that acts as a liaison between the user and the that acts as a liaison between the user and the computercomputer

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• Utilities • a category of system software that augment the

operating system by taking over some of its responsibility for allocating hardware resources

• Device drivers• handle the transmission protocol between a computer

and its peripherals• when you add a device to an existing computer, part of

its installation includes adding its device driver to the computer’s configuration

• Programming languages• used by a programmer to write computer instructions • the instructions are translated into electrical signals that

the computer can manipulate and process.

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Understanding Application Understanding Application SoftwareSoftware

• Application software

• enables you to perform specific computer tasks

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Understanding Application Understanding Application SoftwareSoftware• Document production software

• includes word processing software, desktop publishing software, e-mail editors, and Web authoring software

• has a variety of features that assist you in writing and formatting documents, including changing the font (the style of type) and spell checking to help you avoid typographical and spelling errors

• Spreadsheet software • a numerical analysis tool• used to create a worksheet composed of a grid of

columns and rows• you type data into the cells, and enter mathematical

formulas into other cells that reference the data

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Spell checking a documentSpell checking a document

A wiggly red line indicates a possible spelling error

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Typical worksheet with numerical data and a graphTypical worksheet with numerical data and a graph

Cell B5 contains result of calculation performed by spreadsheet software

Graph

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Understanding Application Understanding Application SoftwareSoftware• Database management software

• lets you collect and manage data

• Database • a collection of information stored on one or more

computers organized in a uniform format of records and fields

• record—a collection of data items in a database• field—one piece of information in the record • An example of a database is the online catalog of

books at a library; the catalog contains one record for each book in the library, and each record contains fields that identify the title, the author, and the subjects under which the book can be classified.

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Understanding Application Understanding Application SoftwareSoftware• Graphics softwareGraphics software

• allows you to create illustrations, diagrams, allows you to create illustrations, diagrams, graphs, and chartsgraphs, and charts

• Presentation softwarePresentation software• allows you to project a presentation before a allows you to project a presentation before a

group, print it out for quick reference, or group, print it out for quick reference, or transmit it to remote computerstransmit it to remote computers

• Clip artClip art• simple drawings that are included as simple drawings that are included as

collections with many software packagescollections with many software packages

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Understanding Application Understanding Application SoftwareSoftware• Photo editing software

• allows you to manipulate digital photos• you can make the images brighter, add special

effects to the photo, add additional images to a photo, or crop the photo to include only relevant parts of the image

• Multimedia authoring software • allows you to record digital sound files, video

files, and animations• Web site creation and management software

• allows you to create and manage Web sites

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• Information management software

• keeps track of schedules, appointments, contacts, and “to-do” lists

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Understanding Object Linking and Understanding Object Linking and Embedding (OLE)Embedding (OLE)

• Object linking and embedding (OLE) • refers to the ability to use data from another file, called

the source• Embedding

• occurs when you copy and paste the source data in the new file

• Linking • allows you to create a connection between the source

data and the copy in the new file• the link updates the copy every time a change is made

to the source data• Integration

• the seamless nature of OLE among some applications

Documents

Understanding Essential Computer Concepts. 2 Investigate types of computersInvestigate types of computers Examine computer systemsExamine computer systems