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1. Unit 1—Computer Basics
Lesson 1
Understanding Computers and
Computer Literacy

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Objectives
⚫ Discuss the history of computers.
⚫ Define the term computer and describe a
computer system.
⚫ Describe the five computer classification
categories.

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Objectives (cont.)
⚫ Describe the two types of computer
software.
⚫ Describe communications and networks.
⚫ Identify how we use computers and
technology in our daily lives

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Introducing Computers
⚫ Computers are considered one of the most
important conventions of the 20th century.
⚫ Their widespread use affects us individually
and as a society.

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A Brief History of the Computer
•The first computers were
developed in the late 1940s
and early 1950s.
•In 1971, Dr. Ted Hoff
developed the microprocessor.
•Steve Jobs and Steve
Wozniak built the first Apple
computer in 1976.
The IBM PC was
introduced in
1981.

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What Is a Computer?
⚫ A computer is an electronic device that
⚫ Receives data (input)
⚫ Processes the data it receives
⚫ Stores the data in memory or on some
storage device, such as a disk or CD
⚫ Outputs information on a device, such as a
monitor or printer

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What Is a Computer System?
⚫ A computer system includes hardware, software,
data, information, and people.
⚫ Hardware: The machine including the wires, transistors, and
so on
⚫ Software: Instructions or programs that control the computer
⚫ Data: Text, numbers, sound, images, video
⚫ Information: Output
⚫ People: Users of the computer

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The Processing Cycle of a
Computer
This figure shows the typical processing cycle of a computer.
Once it receives a set of data, the computer processes it and
produces a result at the end of the cycle.

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Are Computers Intelligent?
⚫ As complex as some computers may be, they
all essentially perform two operations:
⚫ Arithmetic operations such as addition,
subtraction, multiplication, and division
⚫ Logical operations, such as comparing two values
and taking some action based on the result of the
comparison
⚫ Greater than, less than, or equal to

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What Makes a Computer So Powerful?
⚫ Although computers perform only basic operations,
they
⚫ Perform those functions very quickly
⚫ Produce accurate and reliable results
⚫ Store large amounts of data
⚫ Provide versatility through various applications
⚫ Share resources with other computers
⚫ Are becoming more powerful and easier to use

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Classifying Computers
⚫ Two categories of computers:
⚫ Special purpose
⚫ Used to control devices, such as radar
detection or a microwave oven
⚫ General purpose
⚫ Five categories based on size, function, cost,
and performance

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General-Purpose Computers
⚫ Desktop: Personal computer in which all
components fit on or under a desk
⚫ Mobile: Personal computers, such as notebook
computers and tablet PCs
⚫ Mid-range server: Used by medium-sized
companies; generally supports hundreds of
users

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General-Purpose Computers
(cont.)
⚫ Mainframes: Large, very expensive machines that can support
thousands of users; used by large corporations
⚫ Supercomputers: Used for specialized operations requiring
mathematical operations

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Types of Personal Computers
Desktop Computer Notebook Handheld

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Computer Software
⚫ Two basic types
⚫ Application: Performs specific tasks for
users (example: word processing)
⚫ System: Software that controls the
computer’s operating system (example:
Microsoft Windows)

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Electronic Communications
⚫ Electronic communication is the
technology that allows computers to talk
to each other and to other devices.

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Electronic Communications (cont.)
⚫ The four components of electronic communication are
⚫ Sender: The computer sending a message
⚫ Receiver: The computer receiving the message
⚫ Channel: The media that carries the message
⚫ Protocol: The rules that govern the processing of a message
between computers

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Electronic Communication Components
Computer A sends a message to Computer B.
The message travels via the channel, following the rules defined by the protocol being used so that
each computer can understand the message.

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Network Systems
⚫ A network consists of multiple computers
connected to each other to share data and
resources.
⚫ Data and software programs usually are stored on
a central computer called a server.
⚫ When network computers are located in the same
general area, such as the same building or a
department, it is called a local area network.

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A Typical Network Layout
In a typical network layout, the client or user computers are connected to a
hub, which also is connected to the server.
Client or user computers
Data and programs are
stored on the server. All
clients can access data
and pro-grams through
the server and can
access the printer
attached to the server.
Hub

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Other Types of Networks
⚫ Some other types of networks in common use today
are as follows:
⚫ Intranet: This is a network that may be set up for
employees of a business or students at a university that is
not accessible to users outside of those institutions.
⚫ Extranet: This typically is an intranet that allows certain
users, such as suppliers or customers, to access the
internal network.

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The Internet
⚫ The Internet evolved from a government research
project that enabled the military and scientists around
the world to share information.
⚫ Today, it is the largest network in the world.
⚫ Millions of people use it daily.
⚫ It is a critical and valuable business tool used by businesses
of all sizes.

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Technology for Everyday Life
⚫ Examples of the ways in which our lives are
affected by computers daily:
⚫ Electronic security systems
⚫ Games
⚫ Government research operations
⚫ Computerized appliances

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Computers in Our Future
⚫ Computers of the future will be
⚫ Less expensive
⚫ More powerful
⚫ More people will work from home.
⚫ Wireless devices will be commonplace.

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Summary
⚫ Computers have been around for more than 60
years.
⚫ A computer is an electronic device that receives
data, processes data, and produces information.
⚫ A computer derives its power from its speed,
reliability, accuracy, storage, and communications
capability.

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Summary (cont.)
⚫ Computer classifications include personal computers
(desktop and notebook), mobile devices, mid-range
servers, mainframes, and supercomputers.
⚫ The two basic types of software are application
software and system software.
⚫ Electronic communications enable computers to
communicate with each other and other devices.

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Summary (cont.)
⚫ A network is a group of two or more connected
computers, an intranet is a closed network within an
organization, and an extranet is a closed network for
an organization and its customers and suppliers.
⚫ The Internet is the world’s largest network.

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Summary (cont.)
⚫ Computers and technology affect almost
every facet of our daily lives.
⚫ Computers in our future will be more powerful
and less expensive.
⚫ Computer literacy is the ability to use a
computer and its software to accomplish
practical tasks.