1. Basic concepts of Information technology
By: Norah Alsufyan
Basic concepts of Information technology
Ch:4

2. Contents Computer definition Types Of Computer Data Representation
By: Norah Alsufyan
Contents
Computer definition
Types Of Computer
Microcomputers
Midrange computers
Mainframes
Supercomputers
Data Representation

3. Contents Computer System Network Hardware Software Type of Networks
By: Norah Alsufyan
Contents
Computer System
Hardware
Computer Hardware Components
System unit
CPU
Memory
Storage
Input and output
Software
System software
Application software
How Software is Made
The Graphical User Interface (GUI)
Network
Type of Networks
The internet

4. By: Norah Alsufyan
Computer definition

5. By: Norah Alsufyan
What is a Computer?
A computer is an electronic device that accepts information and instructions from a user, manipulates the information according to the instructions, displays the information in some way, and stores the information for retrieval later.

6. Types Of Computer Computers come in four sizes: Microcomputers
By: Norah Alsufyan
Types Of Computer
Computers come in four sizes:
Microcomputers
Midrange computers
Mainframes
Supercomputers

7. By: Norah Alsufyan
Types Of Computer
Microcomputers: is a small, relatively inexpensive computer ,the most common of all, easily outsells all other types of computers annually for use in business and at home.
Five types of Microcomputers:
Desktop Computers
Notebook Computers/Laptop Computers
Tablet
Handheld computer , such as : smartphone

8. By: Norah Alsufyan
Types Of Computer
Mainframes are a type of computer that generally are known for their large size, amount of storage and processing power.
More powerful and larger than a microcomputer.
Primarily used by large organizations for mission-critical applications requiring high volumes of data processing , such as census , consumer statistics and financial transaction processing.
Midrange computers is a computer smaller than a mainframe, but larger than a microcomputer.
A medium-sized computer
Computers that are more powerful and capable than microcomputer computers but less powerful and capable than mainframe computers.

9. By: Norah Alsufyan
Types Of Computer
Supercomputers: The most powerful and largest computers
Supercomputers were designed to solve problems consisting of long and difficult calculations.
Example: NASA and Weather forecasting

10. By: Norah Alsufyan
Data Representation
Data representation refers to the internal method used to represent various types of data stored on a computer.

11. By: Norah Alsufyan
Data Representation
Data refers to the words, numbers, figures, sounds, and graphics that describe people, events, things, and ideas
Binary digits (bits) value is either 0 or 1
A series of eight bits (8 bits) is called a byte
Kilobyte (KB or K) = 1024 bytes
Megabyte (MB) = approx. one million bytes
Gigabyte (GB) = approx. one billion bytes
Terabyte (TB) = approx. one trillion bytes
ASCII – American Standard Code for Information Interchange

12. Computer System A computer system consists of : hardware software
By: Norah Alsufyan
Computer System
A computer system consists of :
hardware
software

13. By: Norah Alsufyan
Computer System
System: A set of components that interact to accomplish a purpose.
A computer system consists of two major elements which are complement each others:
Hardware refers to the physical components of a computer
Example : mouse , CPU, memory and monitor.
Software refers to the intangible components of a computer system, particularly the programs, or lists of instructions, the computer needs to perform a specific task
Example : Windows and Microsoft word.

14. By: Norah Alsufyan
Hardware
Physical components of a computer

15. Computer Hardware Components
By: Norah Alsufyan
Computer Hardware Components
A typical computer is made up of:
–  The motherboard is the main electronic component of the computer
–  System Unit
–  Keyboard
–  Monitor
–  Mouse
–  Multimedia Devices
Computer hardware designed to display, store, record or play multimedia content such as photos, music and videos.
Types of multimedia devices include microphones, speakers, cameras and headphones.

16. System Unit The central component of the system
By: Norah Alsufyan
System Unit
The central component of the system
The Processor: corresponds to the CPU
Memory: RAM and ROM
Storage: Hard Disk or Removable Storage devices

17. By: Norah Alsufyan
The Processor (CPU)
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program.
CPU is your computers brain.
The processor tells your computer what to do and when to do it.
Does the calculations
Speed is very important – measured in megahertz (MHz): the faster the processor the more calculations performed per second.

18. By: Norah Alsufyan
Memory
Memory is any physical device capable of storing information temporarily or permanently.
Measured in bytes
 One byte = eight bits
 Types of memory:
Random Access Memory (RAM) : Volatile memory
Cache memory(RAM cache or CPU cache) : - Volatile memory
Virtual memory: Volatile memory
Read-only memory(ROM) : nonvolatile memory

19. Types Of Memory Random Access Memory (RAM)
By: Norah Alsufyan
 Types Of Memory
Random Access Memory (RAM)
Used by the Computer as the working area
Holds the working program, the data being processed and the interim results
Volatile - contents are erased if power is cut
Can be accessed randomly: can get any piece of data directly.
Faster than permanent storage
Not to be confused with ROM (Read-Only Memory)

20. Types Of Memory Cache memory (CPU memory)
By: Norah Alsufyan
 Types Of Memory
Cache memory (CPU memory)
Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM.
This memory is typically integrated directly with the CPU chip or placed on a separate chip that has a separate bus interconnect with the CPU.
Volatile - contents are erased if power is cut
Virtual memory
Virtual memory meant the idea of using disk to extend RAM.

21. Types Of Memory Read-only memory(ROM)
By: Norah Alsufyan
 Types Of Memory
Read-only memory(ROM)
Once data has been written onto a ROM chip, it cannot be removed / modified and can only be read since these instructions do not need to be changed very often.
Read-only memory (ROM) contains the instructions for what needs to happen when a computer is powered on.
Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.

22. By: Norah Alsufyan

23. By: Norah Alsufyan
Storage
Saved permanently- records and stores all programs and data / information
Types of Storage media
Hard Disk
Optical storage device
- CD – DVD – CD-R
– CD-RW –DVD-RW – DVD-R – CD-ROM
Flash memory
Flash memory cards
USB flash storage device

24. By: Norah Alsufyan
Input and Output
The data or instructions you type into the computer are called input
The result of the computer processing your input is referred to as output
Peripheral devices accomplish input and output functions

25. By: Norah Alsufyan
Input Devices
You use an input device, such as a keyboard or a mouse, to input data and issue commands
– Keyboard
– Pointing device :controls the pointer
Mouse
Trackball
Touchpad
Pointing stick
– Touchscreen
– Scanner

26. Output Devices Output devices show you the results of processing data
By: Norah Alsufyan
Output Devices
Output devices show you the results of processing data
Monitor
LCD
LED
Printer
Laser
Inkjet
Dot matrix

27. By: Norah Alsufyan
Software
Intangible components of a computer system

28. Software Generic name of all programs
By: Norah Alsufyan
Software
Generic name of all programs
Made up of code interpreted by the hardware
Written in programming languages - Java, C and C++
Two kinds of Software:
System
Application

29. By: Norah Alsufyan
System Software
System software helps the computer carryout its basic operating tasks.
Concerned with the computer itself: devices, file and storage management.
Main piece of System software : Operating System (OS)
Operating System (OS): the driving program of the computer
– OS has Multitasking features
–  communicates between all programs and the hardware
–  manages data to ensure security and integrity
–  Examples: Windows, Mac OS, Unix

30. Applications Software
By: Norah Alsufyan
Applications Software
Application software enables you to perform specific computer tasks, such as document production, spreadsheet calculations, and database management
Used for the things you want the computer to do
Common Examples - Word, Excel, Internet Explorer

31. By: Norah Alsufyan
How Software is Made
Involves a cycle of research, analysis, development and testing
Systems Analysts - study the business processes and designs the software
Programmers - develops the software

32. The Graphical User Interface (GUI)
By: Norah Alsufyan
The Graphical User Interface (GUI)
Represents all the program / computer resources as icons
Workspace represented graphically
More usable: led to wider use of computers

33. By: Norah Alsufyan
Networks

34. By: Norah Alsufyan
Networks
A network connects one computer to other computers and peripheral devices, enabling you to share data and resources with others.
Network interface card(NIC) is a circuit board or card that is installed in a computer so that it can be connected to a network. 

35. Type of Networks local area network (LAN )
By: Norah Alsufyan
Type of Networks
local area network (LAN )
is a group of computers and network devices connected together using wired , usually within the same building
A wireless local area network (WLAN)
is a group of computers and network devices connected together wirelessly , usually within the same building
LAN refers to a wired network while WLAN is used to refer to a wireless network.
LAN is much faster compared to WLAN.
LAN is more secure compared to WLAN.

36. Type of Networks Wide area network (WAN) Personal area network (PAN )
By: Norah Alsufyan
Type of Networks
Wide area network (WAN)
refers to a network which covers a large geographical area
A WAN connects several LAN
The Internet is an example of a worldwide public WAN.
Personal area network (PAN )
is a computer network used for data transmission amongst devices such as computers, telephones, tablets and personal digital assistants.
Example : Bluetooth

37. By: Norah Alsufyan
The Internet
The Internet is the largest network in the world, connecting millions of people.
Internet usage
World Wide Web
Web page \ collection of web sites