1. Computer and Internet Basics
Unit A

2. What is a computer?
A computer is a device for processing data. More precisely a computer is a device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions.
A program is a set of instructions to perform a task.

3. A Computer is a device that
accepts input
processes data
stores data
produces output
(all according to a series of stored instructions)

4. Computer System Peripherals Computer +
input devices + output devices + storage devices

5. Computer System

6. Computer system consists of:
Hardware includes the electronic and mechanical devices that process data. Examples: microprocessor, key board.
Peripheral devices expand the computer’s input, output, and storage capabilities.
Examples: Printers.
Software: programs

7. Computer Network
A computer network consists of two or more computers and other devices that are connected for the purpose of sharing data and programs.

8. LAN
A LAN (local Area network) is a computer network that is located within a limited geographical area, such as a building or campus.

9. COMPUTER FUNCTIONS
Computer Input is whatever is put into a computer system.
Input can be supplied by a person, by the environment, or by another computer.
Data refers to the symbols that represent facts, objects, and ideas.

10. COMPUTER FUNCTIONS
Computer manipulate data in many ways, and we call this manipulation processing

11. COMPUTER FUNCTIONS
The instructions that tell a computer how to carry out the processing tasks are referred to as a computer program.
In a computer most processing takes place in the central processing unit (CPU) (also known as microprocessor)
A computer stores data so that it will be available for processing.
Memory is an area of a computer that temporarily holds data waiting to be processed, stored, or output.
Storage is the area of a computer that holds data on a permanent basis when it is not immediately needed for processing.

12. Computer Functions
Words, symbols, numbers, sound, pictures, program instructions
Input
Program calculates, sorts modifies data
Uses microprocessor or CPU
Process
Results of processing
Reports, graphs, documents, pictures
Printer or monitor
Output
Memory is temporary holding area (RAM)
Storage is permanent (disk)
Store

13. Categorizing Computers
Cost
Usage
Size
Capability

14. Less Powerful Computers
PC/microcomputer
Workstations
Handheld computer/PDA
CD: video on PDA
Videogame console
Sony PlayStation®

15. Personal Computer
A PC is designed to meet the computing needs of a person. It typically provides access to a wide variety of computing applications, such word processing, photo editing, , etc.
There are four types: desktop, notebook computers, workstations, and video game console.
Workstations are usually powerful desktop computers for special purposes.

16. Servers
The purpose of a server is to serve the computers on a network by supplying them with data.
A PC, workstation, mainframe or supercomputer can work as a server.

17. Mainframes
A mainframe is a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users.
Mainframes are used by businesses, universities, or governments to provide centralize storage, processing and management of large amount of data.

18. Supercomputers
A computer is a supercomputer if, at the time of construction, it is one of the fastest computers in the world.
Supercomputers are used in complex tasks such as breaking codes or climate modeling.
The CPU of a supercomputer contains thousands of microprocessors.

19. Computer System Peripherals Computer +
input devices + output devices + storage devices

20. System Unit
The system unit is the case that holds the power supply, storage devices, and the circuit boards, including the main circuit board (also called the “mother board”), which contains the microprocessor.

21. System Unit
Power Supply
Storage Devices
Circuit Boards

22. Input/Output Devices Monitor Keyboard Mouse Modem Printer
Speakers/sound card

23. Notes
You can use a modem to establish an Internet connection using an standard telephone line.
Computers have many types of storage devices that are used to store data when the power is turned off.

24. Storage Devices Floppy disk drive Hard disk drive CD-ROM drive
DVD drive
CD writer

25. Storage Devices
A floppy disk drive is a storage device that reads data from and writes data to a floppy disks.
A hard disk drive can store billions of characters of data.
A CD-ROM drive is a storage device that uses that uses laser technology to read data that is permanently stored on data or audio CDs.
A DVD drive can read data from CDs DVDs, or DVD movie discs.

26. Data vs. Information Data (symbols) used by computers
Information (meaningful) used by people

27. Data
Computers process and store data using the binary number system and several other codes designed expressly for electronic data.
Binary number system has only two digits 0 and 1.
Each 0 and 1 is a Bit.
Byte (8 bits)

28. Files Collection of data on a storage medium Data file (passive)
Executable file (active)
Filename and extension
Image.jpg
Word.exe
Resume.doc

29. Software
Application Software is a set of computer programs that helps a person carry out a task.
System Software is a set of computer programs that helps a computer carry out basic tasks.

30. System Software
Helps the computer monitor itself in order to function efficiently
Operating system
Master controller of all computer activities
Popular operating systems
PCs: Microsoft Windows, Mac OS
Handhelds: Windows CE and Palm OS
Servers: Linux and UNIX
CD video: windows interface

31. Computers that operate in essentially the same way are said to be compatible.
Two of the most important factors that influence the compatibility of two computers are the microprocessor and the operating system.
A platform consists of the underlying hardware and software of the computer system.

32. Platform Mac and PC compatibility is an issue
Microprocessor + Operating system
Mac and PC compatibility is an issue
Apple computer = Mac platform
Original IBM computer = Windows or PC platform
Info web: Apple computers

33. Designed to carry out a particular task
Application Software
Microsoft Excel
Microsoft PowerPoint
Designed to carry out a particular task

34. Internet Basics (Cyberspace)
Internet is a collection of local, regional, national and international computer networks that are linked together to exchange data and distribute processing tasks.
Infoweb: cyberspace
Infoweb: internet resources

35. Internet Terminology
The Internet backbone defines main Internet routes
route= telecommunication link
Constructed and maintained by major telecommunications companies.
TCP/IP is a standard set of rules for electronically addressing and transmitting data.
Transmission Control Protocol/ Internet Protocol

36. Internet Backbone

37. Internet Terminology
IP Address: unique number for each Internet computer
Packets: small chunks of data ready to travel the Internet
Router: helps send along the packets to correct destination
CD screentour: web sites provides files

38. Internet Resources Internet Telephony Usenet E-commerce
Instant Messaging
Web Sites
Internet Radio
Download Or Upload
Chat Groups

39. Modem Internet Connections
Dial-up connection via modem requires a modem, which converts your computer’s digital signals into a type of signal that can travel over phone lines.
The maximum speed is 56Kbps, or 56,000 bits per second.
, E-commerce, and chat.
Infoweb: national ISPs
Lab: making a dialup connection
CD video: computer modems

40. Faster Internet Connections
ISDN (Integrated Services Digital Network) provides data transfer speeds of either 64K or 128K.
Always-on and expensive
DSL (Digital Subscriber Line) is a generic name for a family of high –speed Internet links, including ADSL, SDSL, and DSL lite.
Up to 125 times faster than dialup
Both ISDN and DSL connections require proximity to a telephone switching station.

41. Internet Service Provider (ISP)
An ISP is a company that maintains Internet computers and telecommunications equipment in order to provide Internet access to businesses, organizations and individuals
User ID and password required
account monthly fee
Should have local access telephone numbers

42. World Wide Web Basics
The web (or World Wide Web) is a collection of files that are interconnected through of hypertext.
Hypertext: text, video, pictures.
A Web pages is a collection of hypertext documents and links (or hyperlinks).
A link is a related document.
A web site is a collection of web pages with an Internet address.
A Web server is a computer that stores and distributes web pages.
Infoweb: hypertext

43. World Wide Web Basics http://www.cnn.com/showbiz/movies.htm
URL (uniform resource locator) is the internet address of a web site.
HTTP ( Hypertext Transfer Protocol) is the communications standard that is used to transport web documents over the Internet.
HTML (Hypertext Markup Language) is a language to create web pages.
.htm or .html file extension
Document name
and filename
extension
Folder
name
Web
server
protocol
standard

44. Browsers and Search Engines
A browser is a software program that runs on your computer and helps you access web page.
A search engine refers to a web site that provides a variety of tools to help you find information on the Web.
Infoweb: browser
Lab: browsing and searching
Microsoft Internet Explorer® and Netscape Navigator®

45. Computer and Internet Basics
End