COMPUTER SKILLS Chapter 1: Basic Concepts of IT 1

What is a Computer? 2 Computers:  Are Information Processing machines used in different departments and organizations.  Can be connected all over the world.  More productivity and quality with less cost.  Legal Constraints.

What is a Computer? 3 Computers… Perform 3 major operations:  Receive input (DATA: raw facts).  Process it according to predefined instructions.  Produce output (INFORMATION: meaningful data).

Computer System Components Hardware Physical Components (e.g. Screen, Keyboard, etc.) Cannot do anything without software Software Set of Instructions that tell the computer what to do and how to do it e.g. Games, Word Processing, etc. Users Uses software on the computer to perform some tasks. 4

Information Technology 5 IT…  Set of tools used to receive, process, store, retrieve, print and transmit information in an electronic form through computers.  Forms can be: text, sound, picture or video.

Computer Types 6 Types of Computers according to capacity & performance: Super Computers Mainframes Mini Computers Personal Computers LaptopsPalmtops Network Computers

Computer Types 7  High capacity computers that cost million of dollars.  Often used for research.  E.g. weather forecasting, oil exploration, aircraft design. Supercomputers:

Computer Types 8  Room-sized, expensive, high speed, very powerful, large storage capacities and occupy special air- conditioned rooms.  Used in: Banks, Government depts. and large organizations.  Connected to a large no of Terminals that could be:  Dumb: cannot operate on their own.  Intelligent: have a processing power by themselves that can be used by the user. Mainframes:

Computer Types 9  Same job of mainframes but on a smaller scale.  Used by medium-sized companies for specific purposes (where PCs would be inadequate) such as accounting. Mini Computers:

Computer Types 10  Can be set on a desk, not expensive  very popular.  Manufactured under different names:  IBM Compatible: can run same programs as computers made by IBM.  Macintosh Computers: use operating systems made by Apple only. Personal Computers (PCs):

Computer Types 11  Small, briefcase-sized & portable.  Small screen, small keyboard.  Powerful as PCs but very expensive. Laptop Computers :

Computer Types 12  A hand-held computer, small screen & keyboard. It performs special functions & considered to be cheap.  Personal Digital Assistants (PDAs) is a good example of Palms.  PDAs are small pen controlled handheld computers that uses special pen & a touch-screen.  PDAs can be used to:  Send & receive faxes & s.  Write Memos.  Keep appointment calender. Palmtop Computers :

Computer Types 13  A large PC-type computer called a SERVER is connected to smaller PCs called CLIENTS or TERMINALS. Network Computers :

Parts of a Personal Computer System Unit: contains the following:  Mother Board or System Board.  Memory: temporarily stores applications, documents and stem operating information.  Power Supply: changes normal electricity into electricity that a computer can use.  Port: a socket on the outside of the system unit connected to the inside of system unit. There are SERIAL, PARALLEL,SCSI and USB ports.

Parts of a Personal Computer System Unit: (cont…)  Expansion Slots: sockets on the mother board into which an Expansion Board can be plugged.  Expansion Board (Card or Adapter): circuit boards that provide more memory or control peripheral devices. (e.g. Graphic Card, Sound Card, Modem…etc.)  Device Controller: circuit boards that allows computer to work with different kinds of devices (hard & floppy disks, Monitor, Keyboard …)  Disk Drives: a device that read from & write to disks. Floppy disk drive. Hard Disk drive.

Parts of a Personal Computer System Unit: (cont…)  System Clock: Controls time performing all the operations within a computer. The faster the clock, the faster the processing  Light Emitting Diodes (LED): small light sources used to indicate that the equipment is switched on, and the level of activity. System Units can be a vertical Tower or a horizontal Desktop.

Parts of a Personal Computer Input Devices:  Allow to put data into the computer in a form that a computer can use.  Keyboard, Mouse. 3. Output Devices:  Devices that translates the information processed by the computer into a form that humans can understand.  Monitor. 4. Peripherals:  Any piece of hardware connected to a computer to perform special Input or output tasks.  Printer, Scanner, Modem.

System Unit 18