Computer Science

What Is a Computer?

 A computeris an electronic device, operating under

the control of instructions stored in its own memory

 

The Components of a Computer

A computer contains many electric, electronic, and mechanical components known as hardware

Input Device

Allows you to enter data and instructions into a computer

Output Device

Hardware component that conveys information to one or more people

System Unit

Case that contains the electronic components of the computer that are used to process data

Storage Device

Holds data, instructions, and information for future use

Communications Device

Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices

Advantages and Disadvantages of Using Computers

• Speed
• Reliability
• Consistency
• Storage
• Communications
• Disadvantages of Using Computers
• Health Risks
• Violation of Privacy
• Public Safety
• Impact on Labor Force
• Impact on Environment
• Green computing : involves reducing the electricity consumed and environmental waste generated when using a computer
• Strategies include
• Recycling
• Regulating manufacturing processes
• Extending the life of computers
• Immediately donating or properly disposing of replaced computers

Networks and the Internet

A network is a collection of computers and devices connected together,
often wirelessly, via communications devices and transmission media

The Internet is a worldwide collection of networks that connects millions of
businesses, government agencies, educational institutions, and individuals

People use the Internet for a variety of reasons

• Communicate
• Research and Access Information
• Shop
• Bank and Invest
• Online Trading
• Entertainment
• Download Music
• Share Videos
• Web application

Categories of Computers

Personal computers

• A personal computer can perform all of its input, processing, output, and storage activities by itself

• Two popular architectures are the PC and the Apple

• Desktop computer

Mobile computers and mobile devices

Mobile Computer

• Personal computer you can carry from place to place
• Examples include notebook computers, laptop computers, and Tablet PCs

Mobile Device

• Computing device small enough to hold in your hand

• Examples include smart phones, PDAs, handheld computers, portable media players, and digital cameras

Game consoles

• A game console is a mobile computing device designed for single‐player or multiplayer video games

Servers

• A server controls access to the hardware, software, and other resources on a network

• Provides a centralized storage area for programs, data, and information

Mainframes

• A mainframe is a large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously

Supercomputers

• A supercomputer is the fastest, most powerful computer

• Fastest supercomputers are capable of processing more than one quadrillion instructions in a single second

Embedded computers

• An embedded computer is a special‐purpose computer that functions as a component in a larger product

Computer Applications in Society

• Education
• Finance
• Government
• Health Care
• Science
• Publishing
• Travel
• Manufacturing

Summary

•  Basic computer concepts
•  Components of a computer
•  Networks, the Internet, and computer software
•  Many different categories of computers, computer users, and computer applications in society