Computer Hardware and Software
Some DefinitionsHardware: The physical components of a computer
system. Hardware is tangible, it can be touched.Peripherals:
Devices that are attached to a computer system. Keyboard, mouse and
monitor are common computer peripherals.Software: The instructions
(computer programs) and associated data that are needed for a
computer to do useful work.ComputerA computer is just a machine. It
may be a very versatile, useful machine, but that's all there is to
it. To be precise it is an electronic machine desgned to process
large amounts of digital data very quickly and
accurately.StorageData can be stored on a variety of different
media: floppy disks, CD-RW, USB 'flash disks' and the computer's
own hard disk are common ways to store data. Each has their own
advantages and limitations in terms of reliability, speed, capacity
and availability.OutputOutput from a computer is usually seen via a
monitor screen or printed hardcopy. Your choice of monitor and
printer will also depend on a number of factors including price and
resolution needed.Questions1. Make a list of different storage
media and compare the price you pay for a megabyte of storage on
each one. Does anything surprise you?NetworksNetwork: a network
allows several computers to share hardware, software and data
stored on any specific machine. Networks are divided into two main
groups:Local Area Networks (LANs): where all machines are
physically connected to eachother. Typically, all the machines will
be fairly close to eachother, but not necessarily in the same room
or even building.Wide Area Networks (WANs): where computers
communicate with eachother via telephone lines or wireless
transmission.Advantages of Using a NetworkThere are many reasons
why a business may choose to install a network, including: Cost: a
business does not need to buy expensive hardware for each
individual machine. Also, site licenses for network versions of
applications software may be cheaper than several individual
licenses. More significantly, less office space is needed for
peripherals when several machines can all share a printer.
Efficiency: instead of having to make multiple copies of documents,
a single version can be made available to everyone over a network.
When this file is updated, everyone has access to the new document
at the same time. With all technologies, there are risks. By adding
a network, a company may experience: Hacking: people might attempt
to gain unauthorized access to sensitive material stored on the
network . Vulnerability to Virus Programs: an infected file shared
across a network has the potential to infect a large number of
machines very quickly.Peer to Peer NetworkingMany networks rely on
one specific machine storing all data that is shared between the
terminals connected to it (a file server). However, modern
peer-to-peer technology allows data to be shared between individual
machines with each of them acting as a server in its own
right.Questions1. List three reasons why a school might choose to
use a network.2. Your cousin is thinking of adding a wireless
network to his home in order to enable him to listen to his
extensive music collection from any room in the house. Write a
letter to him explaining that a network would allow him to do much
more than this (give at least three examples) and also list some of
the security issues he should be aware of if he chooses to do
this.3. Describe five ways in which a network could help a
secretary in a large company do their job more efficiently.4.
Describe two problems that installing a network might cause.
Discuss different ways to overcome those problems.Appropriate Uses
of Application SoftwareApplications software: is general purpose
software that allows you to perform a range of related tasks more
efficiently than you could by using more conventional
technologies.Integrated package: a suite of applications programs
with their associated data and documentation. Typically, it is
usually much cheaper to buy an integrated package than individual
applications programs, it is easier to copy data from one
application in a suite to another (eg import a table of data or a
chart from a spreadsheet into a word-processing document) and the
user interface is similar for the programs in the suite.Common
ApplicationsThere are many different applications programs:
Word-processor: allows you to create, edit, store and print a range
of different text documents; from letters and faxes to books and
essays. Spreadsheet: enables you to use formulas to perform a large
number of calculations on data stored in cells arranged in rows and
columns. You can investigate a mathematical problem, create a
budget plan to forecast how much you can save in a year or model
the results of a science experiment and draw a chart of your
results. Database: uses forms to store data in tables made up of
records and fields. The data can be searched using queries in order
to find out useful information. It can be used to create anything
from an address book to a complex application that produces end of
year reports. Graphics program: can be used to create posters,
perform image processing in order to improve or alter photographs
or create original artwork. DTP software: Desk Top Publishing
software allows you to manipulate text and graphics in frames on a
page in order to create magazines, brochures and other complex
documents. Presentation Software: allows you to create a slideshow
to illustrate a talk, or a presentation for other people to
investigate as a kiosk application. Communications software: could
include a web browser or email client software as well as other
programs that allow you to communicate with FlexibilityWith modern
applications software, there is a great deal of overlap. Many
spreadsheet programs have a range of database functions built in,
and the graphics tools within a word-processor might rival a
graphics program - let alone a DTP package.Questions1. List three
reasons why a school would teach its students how to use
applications software.2. A scientist has an integrated package
installed on his computer. List two different tasks that he could
use a word-processor, spreadsheet, database and communications
software to help him work more effectively.Operating
SystemsSoftware: the programs and data associated with them that
enable your computer to work.Computer program: a set of
instructions which tell a computer what to do.Three Types of
SoftwareComputer programs can be divided up into three different
groups:Applications software: general purpose programs, that allow
you to do a range of tasks more efficiently than if you were to use
conventional methods. Word-processing software, graphics programs
and accounts packages would be examples of applications
software.System software: looks after the way the hardware of the
computer communicates with the user. It controls input, output and
storage devices, manages files and security. Microsoft Windows is
an example of an operating system.Utility programs: are small
programs that just do one specific job. A clock, calculator or
desktop game would be examples of utility programs.Which Operating
System?Most personal computers will have a version of Microsofts
Windows software running as the operating system. However, this is
not the only operating system you may come across. Its Graphical
User Interface (GUI) has its advantages though. It is far easier
for people to learn how to use it to carry out a range of tasks,
just by moving a mouse pointer around on a screen and clicking on
different windows, menus and icons, than it is to learn a set of
commands to type.Computers used for different purposes may use a
variety of operating systems. Many graphic designers will use an
Apple computer with System X, and many web servers will use Linux
as an operating system. Questions1. Describe three different ways a
word-processor can be used to help a teacher with their work.2.
List five different examples of applications software and give one
use for each program.3. Describe two different utility programs you
might find on your computer.4. A friend of yours is thinking of
buying a PC, and wonders what Microsoft Windows is used for. Write
a letter to your friend describing the different features of
Windows and telling them why they need an operating system for
their computer.5. Describe two other operating systems you might
find on a computer, and discuss their advantages and
disadvantages.DatabasesData: can be words, numbers, pictures etc.
It is important to remember that we get useful information from our
raw data by processing it in different ways.Database: a database is
an ordered collection of related data that a user can process in
different ways in order to extract useful information.Computerised
DatabasesUsing a computer to store a database has a number of
advantages:/p> Speed: a computer can search through a large
amount of data much more quickly than a human can. Accuracy:
computers dont get tired, bored or accidentally skip a number of
records. You can be sure that the results found in a computers
database are as accurate as they were when the data was entered in.
Main Features of a Computer DatabaseDatabases are made up of four
main parts: Tables: data is stored in individual tables made up of
records and fields. A relational database will link tables of
related data together so that it can be stored more efficiently.
Records: represent all the data held on an individual item. Fields:
are the different categories into which the data has been
organized. A key field has a unique value for each record in a
database table, it can be used to index the records in the
database. Forms: are used to allow people to enter data easily into
a database. A database form might look very similar to one that
someone has already filled in on paper. Queries: allow a user to
filter out the data that they dont want, and display only those
records which contain data that they are interested in. A simple
query might only search the database for data that matches one
criterion. A complex query is more likely to search for records
that match two or more criteria. Reports: allow you to print just
the data that you want. You can choose to display only those
records matching a query, and only those fields that are relevant
to your search. You may choose to order or group your data in
different ways and add summary details to your printout. This means
that the same database of personal information can be used to print
out address labels, attendance registers and contact lists of names
and telephone numbers grouped by residential area.Questions1.
Describe how a teacher could print out the names of the students in
a year 9 form, if they had a database of all students in their
school. 2. What would be an appropriate key field for a school
library to use in a database of its books?Desktop Publishing
(DTP)DTP: a DTP program allows you to combine text and graphics
using frames to build up multi-column pages, like newspapers,
magazines and brochures. The text and graphics need not be entered
directly into the program, but can be prepared in advance using
word-processing or image-processing software.Frames: are objects on
a page which can be given different colours or borders and into
which text and graphics can be imported. Text frames in a
publication can be linked together so that a story can easily flow
from one frame into another.Advantages of Using DTP SoftwareThere
are a number reasons why a business may choose to use DTP,
including:Cost: a business does not need to hire a commercial
printing bureau to professionally typeset every publication.
Efficiency: instead of having to spend time approving proofs from
an outside printer, the final document can be previewed and changes
made immediately using the company's own hardware and software.
Small printing jobs or re-prints of a publication can be done
quickly by a company's own staff.Disadvantages of Using DTP
SoftwareAs with all technologies, there are disadvantages:Expense:
additional software and hardware may need to be bought. Training:
staff will need to be trained to develop new skills if they are to
use the new hardware and software effectively.HardwareSpecial
hardware is often needed in order to work effectively with DTP
software this could include buying a new printer to cope with the
demand and quality of publications required. Other input devices
might be needed in order to capture images for a publication. Also,
if the final output is to be sent to a printing bureau for a larger
print run, you will need to be able to store and distribute
extremely large files.Questions1. List three different types of
document that could be produced using DTP software.2. Your friend
is thinking of starting a small printing business using DTP
software. Write a letter that he could use to explain to his
customer the advantages of allowing him to produce their brochures
and other promotional material. 3. Describe five items of hardware
(in addition to your computer, monitor, mouse and keyboard) that
could be needed to produce DTP documents.4. Describe two reasons
why a company would prepare documents and images in advance, before
importing them into a DTP program.The Impact of IT in the
HomeRecent advances in information technology have caused a number
of changes in the way that people communicate and spend their
leisure time.CommunicationImprovements in communications
technologies have meant that it is now far cheaper for families and
friends to keep in regular contact including. E-mail: allows you to
not only send text, but you can also attach files, or links to web
addresses where other information can be displayed or downloaded.
Internet telephony/VoIP: using a computer and internet connection
to send and receive sound allows you to take advantage of phone
rates that are far cheaper than international lines. Instant
messaging: allows you to chat by typing in real time with other
people online at the same time as you. Digital photographs: are
shared by family and friends much more easily via CDs, telephones,
email and websites - and if people want an extra printed copy, they
can do it themselves.LeisureWith new technologies, people have new
ways to do a variety of things: Shopping: with a credit card and an
internet connection, you can order food, clothing, books, book
holidays or participate in auctions for antiques, all without
leaving the comfort of your own home, or at 2.00am when local shops
may be closed. Hobbies: users can interact with other fans via
message boards, read news about the latest craze or even create
their own website or fanzine using applications software. Learning:
you can now buy packages to help you learn a new language, revise
for exams, become a better typist or just look up interesting facts
in multimedia encyclopedias. Media: you can record and distribute
your own music (and design the CD cover), create and edit your own
movies and animations, write a play (and perform it online as a
podcast for others to download) or create your own computer
games.Questions1. List three reasons why people use new
technologies to keep in contact with eachother.2. Your cousin is
thinking of producing a magazine about model making. Discuss how
using a computer could help him put together and distribute the
magazine to its readers.3. Describe two problems that.people
sometimes have with online shopping.The Social Impact of IT in the
WorkplaceSocial Impact: using information technology in business
has caused a number of changes in the way that people communicate
and work with eachother. CommunicationsImprovements in
communications technologies have made some issues particularly
interesting: The electronic office: allows people to produce
reports and other documents far more quickly, with greater access
to relevant information. Variety of contacts: people can
communicate by email, fax, mobile phone, pager or any one of
several other methods including teleconferencing - which has the
advantage of being far cheaper than flying several people to the
same conference room.. Responsibility: new laws have been made in
order to make sure that people do not misuse the large amounts of
personal information they now have access to with new technologies,
or to deter them from trying to get unauthorized access to
information they are not entitled to. WorkingWith new technologies,
new practices have been adopted in the workplace this affects
issues like: Training: people might need to be trained to use the
new hardware and software. If they cant learn these new skills,
they might end up without a job. Productivity: using a computer,
more work can be achieved in less time by fewer people. Working
from home: people no longer need to commute into a large city to
work in an office with other employees. New jobs: although some
jobs have disappeared through introducing new technologies, whole
new industries have been created in order to build, maintain, write
software and provide support and training related to IT.
Questions1. A company is upgrading its computer system. Your friend
is worried that they may lose their job as a result. Write a note
to them, outlining some of the possible advantages to them arising
from the upgrade.2. Describe two problems that could result from
personal data being accessed by unauthorized people in a
company.The Social Impact of the InternetThe Internet: A wide area
network of computer networks, allowing the free exchange of large
amounts of data across the world.The Internet is more than the
World Wide Web. You can use the Internet to send and receive
electronic mail, participate in discussions through newsgroups and
even control other computers and devices remotely.Who uses the
Internet?Different people use the Internet to help them do their
jobs in a variety of ways:A lawyer might interrogate a huge
database of the results of cases held in different courts
nationwide.A doctor could get in touch with specialists and
patients when trying to treat extremely rare diseases.A teacher can
control a universitys radio telescope with a science class without
leaving their own classroom.Positive and NegativeAs with all tools,
the Internet is not always used for good purposes. Different
crimes, like identity theft can be done much more easily over the
Internet because people may not realize that they are sending
sensitive personal information to someone who is not who they claim
to be.Questions1. List three jobs that have been created through
the introduction of the Internet.2. List one job which is
threatened by increased use of the Internet.3. Describe five ways
in which different professions have found that using the internet
helps them to achieve much more than before.4. Describe two ways
that the Internet can be used to enhance leisure time.5. Describe
two ways in which the Internet can be misused and discuss the ways
these problems can be dealt with. Computer SecurityComputer Crime:
crimes that are committed with the aid of a computer. For example,
using a computer to commit fraud by identity theft.Hacking:
attempting to gain unauthorized access to someone elses
computer.Phishing: impersonating an official organization in the
hope that the victim will pass on personal information like bank
account details to the fraudster.Pharming: hijacking the way that a
browser finds specific websites over the internet, and pointing a
user to a fraudulent website instead.Virus: a self-replicating
program, written to disrupt the normal use of a computer
system.Trojan: a program which the user runs thinking it will do
one thing, but in reality, it does harm to the computer system.Who
is responsible?You are responsible for the security of your own
computer. However, as with breaking and entering someone elses
property; leaving a door unlocked is unwise, but it does not give a
burglar the right to rob your house.If you do suspect something is
wrong, get expert help and advice quickly. But prevention is far
better than cure.What to do?Much of what you will do is common
sense here are a selection of things to remember. Always keep your
antivirus software up to date. Never open email attachments from
unrecognized senders, and always ask yourself whether a person
known to you is likely to be sending you an attachment. Always use
passwords that are impossible for someone else to easily guess.
Never install software from an unrecognized source - not only
pirated software, but be careful where you download patches and
upgrades to existing programs from. Never give anyone your password
for any service. If they are authorized to investigate something,
they dont need it. If they arent, they shouldnt have it. Always
check warnings you receive via email with an authoritative source
of information. If you receive an offer from someone that seems too
good to be true, it almost certainly is.Questions1. Your best
friend has just lost his entire Social Studies project due to a
virus infection on his computer. What advice would you give him to
ensure that this doesnt happen again?2. List one new job which has
become more important due to the rise in computer security
problems.3. Describe two ways that the Internet can be used to help
you improve your computers security, and one way in which it makes
your system more vulnerable to attack.4. Design a poster to
illustrate some of the computer security advice listed above.
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