Chapter 1
Introduction to the World of
Computers
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Overview

This chapter covers:

What computers do and how they work

Computer terminology

Different categories of computers

Societal impacts of computers
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Computers in Your Life

Computers are prevalent in the home, in the school, in the
workplace, and on the go.

Most professional jobs and skilled trades heavily depend on
the creation, collection, evaluation and dissemination of
information.

Uses of computers include word processing, e-mail
exchange, shopping, research, investments management,
playing games and many other applications.

Knowledge of computers assists the consumer to purchase
the right computer, save money on repairs and use the
computer to maximum benefit.
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What Is a Computer and What Does
It Do?
A computer is a programmable electronic device that
accepts data and performs operations on that data.

Input—entering data into the computer.

Processing—performing operations on the data.

Output—presenting the results.

Storage—saving data, programs, or output for future use.
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Computers Then and Now

The computer as we know it is a fairly recent
invention.

The history of computers is often referred to as
generations, from pre-computers and early
computers (before 1945) to fifth generation
computers (now and the future).

Each new generation is characterized by a major
technological development.
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Hardware

The physical parts of a computer are collectively
known as hardware.

Internal hardware is located within the main box
(system unit) of the computer.

External hardware is located outside the system unit
and plug into connectors called ports located on the
exterior of the system unit.
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Hardware, Cont’d.

An input device is used to input data into the computer.

A processing device performs calculations and comparisons
necessary for processing. The main processing device is the
central processing unit (CPU).

An output device presents the results to the user.

Storage devices are used to save data, programs or output.

Communication devices allow the user to communicate with
others and access remote information.
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Software

The programs or instructions used to tell the
computer hardware what to do.

System software allows a computer to operate and
run application software.

Application software performs specific tasks or
applications.
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Data and Information

Data = raw, unorganized facts.
 Can be in the form of text, graphics, audio, or
video.

Information = data that has been processed into a
useful form.
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Computer Users and Professionals

Computer users, or end users, are the people who
use a computer to obtain information.

Programmers are computer professionals whose job
it is to write the programs that computers use.
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Computer Networks and the Internet

A computer network links computers together so that
users can share hardware, software, and data, as well as
electronically communicate with each other.

Network servers manage resources on a network.

Clients are computers on the network that access
resources via the network server.

Computer networks are commonly found in businesses,
schools, and homes.
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The Internet

The Internet is the largest and most well-known
computer network in the world.

Individuals connect to the Internet using an Internet
service provider (ISP).

E-mail and accessing Web pages are two of the most
common Internet activities.
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Accessing a Network

Need a modem or network adapter to connect to the
network.

Software (often built into the operating system) allows you
to log on to the network and access resources.

Need an ISP and Web browser to access Internet
resources.

Many networks and Internet connections require a user ID
and password to log on to the network.
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Computers to Fit Every Need

Five basic categories

Mobile devices

Personal computers

Midrange servers

Mainframe computers

Supercomputers
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Mobile Devices

Very small computing devices.

Usually based on a wireless phone
or pager.

Many can be used to access e-mail
and Web pages.
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Personal Computers

Microprocessors allow for the creation of computers
small enough to fit on a desk or lap.

PC compatible—based on the original IBM PC;
typically run the Windows operating system.

Macintosh—a type of personal computer
manufactured by Apple.
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Personal Computers, Cont’d.

Desktop computers—small enough
to fit on or next to a desk. Can use:

Desktop case

Tower case

All-in-one case
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Personal Computers, Cont’d.

Portable PCs—designed to be carried around.

Notebook computers

Tablet PCs (either slate or convertible)

Handheld computers (pocket computers)
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Personal Computers, Cont’d.

PCs designed for just network use are referred to as
network computers (NCs) or thin clients.

Devices designed just for Internet access are called
Internet appliances.
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Midrange Servers

Medium-sized computers, also called minicomputers
or midrange computers.

Fall between microcomputers and mainframes in
processing power.
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Mainframe Computers

Standard choice for most large organizations.

Specialize in high-volume processing of business
transactions.

Also called high-end
servers or enterpriseclass servers.
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Supercomputers

Used for applications that have extraordinary demands for
processing power.

Offer very fast speeds and extreme degrees of accuracy.

Commonly created today by
connecting hundreds of
smaller computers
to form a
supercomputing
cluster.
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Computers and Society

The information age = the prominence of information
technology.

There are many benefits of a computer-oriented
society, including making many tasks in our lives go
much faster.

Risks include health, security, ethical, and privacy
concerns.
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Summary

Computers in your life

What is a computer and what does it do?

Computers networks and the Internet

Computers to fit every need

Computers and society
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