Chapter 1 Introduction to the World of Computers

Ubiquitous computing

Ubiquitous computing

refers to embedding information processing and network communication into everyday, human environments to continuously provide services, information, and communication.

Computer Before 1980

Computers were large and expensive, Very few people had access to them, Computers were mostly used for high volume processing tasks

Microcomputers

Inexpensive personal computers, Computer use increased dramatically

Electronic devices

are converging into single units with multiple capabilities

Computers used for a variety of tasks

Looking up information and news – Exchanging e-mail – Shopping and paying bills – Watching TV and videos – Downloading music and movies – Organizing digital photographs – Playing games – Making vacation plans

Wireless networking

Computers can be used in nearly any location

Smart appliances

Traditional appliances with built-in computer or communication technology

Smart homes

Household tasks are monitored and controlled by a main computer in the house

Wireless hotspots

Colleges and universities are even more integrated, Some have computer requirements for enrollment

Computer

A programmable, electronic device that accepts data, performs operations on that data, and stores the data, follows instructions, called programs, which determine the tasks the computer will perform

programs

which determine the tasks the computer will perform

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

Communications

Sending or receiving data

Data

Raw, unorganized facts, Can be in the form of text, graphics, audio, or video

Information Processing

Converting data into information

Information

Data that has been processed into a meaningful form

First-generation computers

(1946- 1957) Enormous and powered by vacuum tubes – Used a great deal of electricity and generated a lot of heat – ENIAC and UNIVAC

Second-generation computers

(1958-1963) Used transistors – Computers were smaller, more powerful, cheaper, more energy-efficient, and more reliable – Punch cards and magnetic tape were used to input and store data

Fifth-generation

(now and the future) Infancy stage – May be based on artificial intelligence (AI) – Will likely use voice and touch input – May be based on optical computers and utilize nanotechnology

Hardware

The physical parts of a computer

Internal hardware

Located inside the main box (system unit) of the computer

External hardware

Located outside the system unit • Connect to the computer via a wired or wireless connection

Input Devices

Used to input data into the computer – Keyboards, mice, scanners, cameras, microphones , touch pads, touch screens, fingerprint readers, etc.

Processing Devices

Perform calculations and control computer’s operation – Central processing unit (CPU) and memory

Output Devices

Present results to the user – Monitors, printers, speakers, projector s, etc

Storage Devices

Used to store data on or access data from storage media – Hard drives, CD/DVD discs and drives, USB flash drives, etc.

Communications Devices

Allow users to communicate with others and to electronically access remote information – Modems, network adapters, routers, etc.

Software

The programs or instructions used to tell the computer hardware what to do

System Software

Operating system starts up the computer and controls its operation

Application Software

Performs specific tasks or applications

Computer Users (end users)

People who use a computer to obtain information

Programmers

Write programs computers use

Systems analysts

Design computer systems

Computer operations personnel

Manage day-to-day computer operations

Security specialists

Secure computers and networks against hackers

Embedded Computers

Embedded into a product and designed to perform specific tasks or functions for that product – Cannot be used as general purpose computers

Mobile Device

A very small device with some built-in computing or Internet capability – Typically has a small screen and keyboard.

Personal Computer (PC)

Small computer designed to be used by one person at a time – Also called a microcomputer – Available in different sizes and shapes

Portable Computers

Designed to be carried around easily – Fully functional computers

Notebook (laptop) computers

Typically use a clamshell design

Tablet computers

Usually use a digital pen/stylus or touch screen • No physical keyboard; can use on-screen or attached keyboard

Netbooks

Smaller and have more limited features than conventional notebooks

Thin Client

Designed to utilize a network for much of its processing – Lower cost, increased security and easier maintenance

Internet Appliance

Specialized network computer designed for Internet access – Some use apps to deliver news, sports scores, weather, music, and other Web-based information

Tech Clothing

Allows you to carry multiple devices safely – Can use devices while they are being worn

Server

A medium-sized computer used to host programs and data for a small network – Sometimes referred to as a minicomputer – Users connect via a network with a computer, thin client, or dumb terminal

Mainframe Computer

Powerful computer used by many large organizations to manage large amounts of centralized data – Standard choice for hospitals, universities, large businesses, banks, government offices

Supercomputer

Fastest, most expensive, most powerful type of computer – Generally run one program at a time, as fast as possible – Can cost several million dollars each

Computer Network

A collection of hardware and other devices that are connected together – Users can share hardware, software, and data – Users can communicate with each other

Network Servers

Manage resources on a network

Internet

The largest/most wellknown computer network in the world – Individuals connect using an Internet service provider (ISP)

World Wide Web

One resource (a vast collection of Web pages) available through the Internet – Web sites contain Web pages stored on Web servers

Internet addresses

are used to access resources on the Internet

IP

(Internet Protocol) address • Numeric address that identifies computers

IP Addresses

Are numeric and unique

Domain Names

Correspond to IP addresses – Top-level domains (TLDs) – Identifies type of organization or its location

Uniform Resource Locators (URLs)

Uniquely identifies a Web page, including

(http://)

Hypertext Transfer Protocol is typically used to display Web pages

(https://

is used for secure Web pages

(ftp://)

File Transfer Protocol is often used for file exchange

Web browser

Used to display Web pages

Browser starting page or home page

The first page displayed when the browser is opened

Search site

Helps you locate what you are looking for – Typically search using keywords

Reference sites

Look up addresses, telephone numbers, ZIP codes, maps, etc.

Electronic mail (e-mail)

Electronic messages exchanged between computers on a network

E-Mail

Can contain photos, attached files, etc. • Mobile e -mail may require a fee