1. Information Technology

2. Computer Generations

3. Computer Generations
The computer passed through develop stages these stages or generation are:

4. Computer Generations First Generation (Vacuum Tubes)
They relied on the machine language to perform operations.
They were huge in size.
They were very expensive.
They had very low processing
speed.

5. Computer Generations Second Generation (Transistors) It is smaller.
It is faster.
It is cheaper.

6. Computer Generations Third Generation (Integrated Circuits)
The speed and the efficiency of the computers were increased.

7. Computer Generations Fourth Generation (Present Microprocessor)
The most powerful.
Can be linked together to form networks.
They are the fastest and the most efficient.

8. Definitions Computer: Information Technology:
A computer is an electronic machine that receives input, stores and automatically processes data, and provides output in a useful format.
Information Technology:
A term that refers to both the hardware and software that is used to store, retrieve and manipulate information.

9. Data: Information: Definitions
Data is raw & unorganized facts and figures that need to be processed.
Information:
When data is processed and organized so as to make it useful and meaningful, it is called Information. .

10. Advantages of computers
Speed and accuracy of calculations and processing.
Save huge amounts of data.
Economic in cost and time.
Network communications.

11. Types of computer

12. Super computer The biggest and the most powerful.
They are rare because of their cost and size.
Used by companies like NASA.

13. Mainframe computer Great processing speed and data storage.
Often connected to many individual PCs with limited processing capabilities called dumb terminals.
Used in Banks, Airlines etc.

14. Minicomputer Minimized in size and power.
They are not used very commonly these days.

15. Microcomputer Called Personal computer (PC)
It is small enough to fit on top of a desk, which can be used by one user at a time.
Used in homes, schools etc..

16. Workstation Computer High-end microcomputer .
Used by one person at a time.
They are commonly connected to a local area network
The workstation term can be also used to refer to a PC connected to a network.

17. Control computer
Used for controlling operations in industrial, medical devices and travel media like planes and cars
Also used to alert in any dangerous case.

18. Parts of Personal computers

19. Computer
Hardware
Software

20. Definitions Hardware:
The physical parts of a computer which you can see and touch.

21. Hardware 1) Input Devices 2) Output Devices 3) Processing Unit
4) Memory Unit
5) Storage Devices

22. Hardware
1) Input Devices

23. 1) Input devices
Devices used to translate the data into a form that the computer can process.

24. a) Keyboard
It is a board containing the keys of letters, numbers and some functions which allows you to type information into the computer.

25. b) Mouse
A small hand-held device used to point, select, click on items and to drag and drop items from one place to another.

26. C) Scanner
It allows you to scan pictures, text and images and save it to your computer in a digital form.

27. d) Bar Code Reader
Photoelectric scanners that translate the bar code symbols into digital form.

28. E) Joystick
Small hand-lever that can be moved in any directions to control movement on the screen.
It can be used for playing games.

29. Hardware
2) Output Devices

30. 2) Output devices
Devices used to translate the processed information into a form that humans can understand.

31. a) Monitor (computer screen)
It displays the text, information and pictures.
They are different in (Size and Resolution)

32. b) Printer
It produces a hard copy of the material you are working on.
Types:
1) Laser Printer ) Ink-jet Printers

33. C) Plotters
It is similar to a printer but allows you to print larger images.

34. D) Speakers / Headphone
They are used to output voice from a computer

35. Note:
Some devices can be used as both Input and output devices at the same time such as:
Touch Screen:
It receives input from the touch of a finger.

36. Hardware
3) Processing unit

37. CPU ( Central Processing Unit )
The most important part of a computer system.
Usually referred to as the brain of the computer.
It determines the speed of your computer which measured in MHz or GHz.
1 GHz= 1000 MHz

38. CPU ( Central Processing Unit )
CPU consists of:
CU (Control Unit): It tells the computer system how to carry out program instructions from the memory. It controls and coordinates all activities of the computer.
ALU (Arithmetic and Logic Unit): It performs mathematical and logical operations

39. Hardware
4) Memory unit

40. a) RAM (Random Access Memory)
The operating system is loaded into the RAM when you switch on your computer.
Used to store applications that you are currently working with.
It is temporary (volatile).

41. b) ROM (read only memory)
It has special programs which are built-in when you buy the computer.
Used to store control programs.
It is permanent (non-volatile)

42. Hardware
5) storage Devices

43. Storage Devices
Hardware devices which are used to record and store data.

44. 1) Internal storage Hard disk:
It is the most important storage media in the computer.
It stores operating system and programs.

45. 2) External Storage a) Flash Memory
A compact and easy-to-use device for transferring data between computers.

46. b) CD (Compact Disk)
An optical disk which uses laser to read information.
It has 750 MB capacity.

47. c) DVD (Digital Versatile Disk)
A high-density video disc that stores large amounts of data, especially high-resolution audio-visual material like movies, encyclopedia etc.
The capacity is up to 17 GB.

48. Disk and memory capacity
The first level of storage is called bit ( the bit is referred to a binary number 0 or 1).
Byte = 8 bits.
Kilo Byte (KB) = 1024 bytes.
Mega Byte (MB) = 1024 KB.
Giga Byte (GB) = 1024 MB.
Tera Byte (TB) = 1024 GB.

49. Computer Performance The speed of the processor. The capacity of RAM.
The capacity and the speed of the Hard disk. 50

50. Software

51. Software
They are instructions that tell the computer what to do and how to do it.

52. Software
Operating System
Application

53. 1) Operating system Examples of operating system:
An interface between hardware and user, which is responsible for the management of activities and the sharing of the resources of a computer.
Examples of operating system:
MS DOS (Disk Operating System)
MS Windows (98 – Me – 2000 – XP – Vista – 7).
MAC OS.
UNIX.

54. Operating system Types
a. CLI (Command Line Interface):
A user interface in which you type commands instead of choosing them from a menu or selecting an icon.

55. Operating system Types
b. GUI (Graphical User Interface):
A visual way of interacting with a computer using items such as windows, icons, and menus.
It is user-friendly. 7

56. Operating system Tasks
Interface:
It provides an interface between the user and the machine.
Resource management:
Allocates computer resources such as CPU time, main memory, secondary storage, and input and output devices for use.

57. Operating system Tasks
Input/output management:
This checks the input and output of the data, their location, storage, and retrieval.
File management:
Setting up directories to organize your files according to their type and displaying a list of files stored on a particular disk.

58. 2) Application Software
Special software to do special functions.

59. Examples of Applications
Word Processor:
It is used to write and format texts, insert tables and pictures, e.g. MS Word.
Spreadsheet:
It is used for automatic calculations and creating charts, e.g. MS Excel.
Database:
A structured set of data held in a computer, e.g. MS Access.

60. Examples of Applications
Web Browser:
A program designed to enable users to access, retrieve and view documents and other resources on the Internet, e.g. Internet Explorer.
Presentation:
It is used to design slides for business and education, e.g. MS PowerPoint.

61. Software and System Development
1- System Analysis
2- System Design
3- Programming