- Hardware : is the parts of computer that you can touch and you can handle.
Example : Keyboard, Monitor, Processor, Speaker, Mouse, Hard disks, ROM/RAM, Printer, web cam. - Software : is the actual programs consisting of instructions that allow hardware to do a useful job.
Example : Operating System, Word processing package, Spreadsheet package, Web browser, Database, CAD (Computer - Aided Design), Web design package, Photo editing package.
The main components of a general - purpose computer
- Input devices (Keyboard, Mouse, digital camera, touch screen, microphone, etc)
Used to get raw data into the computer and ready for processing in the CPU - Output devices (Speaker, printer, monitor, plotters etc)
Used to change information given by the computer into sound of image. - Secondary Storage Devices (Flash disk, DVD R/W drive, portable hard disk drive, etc)
- Processor and internal memory devices.
Central Processing Unit (CPU)
- often called the processor
- it is the brain of computer, it consists of million tiny circuits on a silicon chip
- It controls step-by-step running of the computer system
- it does all the calculation and performs all the logical operations and deals with the data storage and program memory.
Iternal Memory
- ROM (Read Only Memory) : is a fast permanent memory used for holding instructions needed to start up the computer.
* It is held on the computer's chip
* Called non-volatile because file is saved and never lose when the power is off
* Used to hold instructions to start the computer, which are called the boot programs or BIOS
*Used to store data that cannot be altered by the user. - RAM (Random Access Memory) : Is a fast temporary where programs and data are stored when power is supplied.
* Held on the computers chip
* Called volatile memory because contents will disappear when power is off
* Can be written to and read from
* Can be altered by the user
* Holds the software currently used by the user.
Importance of RAM and ROM
Having more memory means:
* Application runs faster on their own
* More application are able to run at the same time
* Application runs faster on their own
* More application are able to run at the same time
* Users are able to move quickly between applications
Operating System (OS)
Are the programs to control the hardware directly by giving step-by-step instructions that tells computer what to do.
USES :
- To handle inputs and outputs
- Recognize hardware
- Supervises running of programs
- Handles the storage of data
- Maximizes the use of computer memory
- Handles interrupts and decides what action to take.
Types of Interface used with operating Systems
- Graphical Users Interface (GUI) : the easy way to use, and have features, such as Windows, Icons, Menus, Pointers, etc.
Windows : the screen that is divided into areas
Icons : Small pictures to represent commands
Menus : Allow users to make selection from list
Pointers : The little arrow that appears while using windows - Command Line Interface/ Driven Interface : The command must be precisely worded, and this is hard to remember how to do this.
Post-Wimp Interactions
- Pinching : you pinch your fingers together to Zoom in or to spread apart to zoom out.
- Rotating : one finger moves up and the other moves down to rotate the subject as an image.
- Swiping : you swipe your finger over the screen to turn over a page.
Different Types of Computer
- Mainframe computers :
* Sophisticated and very strong computer that are used in a very large companies and organizations
* Used to control huge networks
* Have parallelprocessors
Advantage of Mainframe computers:
* Can process huge amount of data
* Data can be processed very quickly
* Can run huge networks with hundreds of terminals
Disadvantages of Mainframe Computer
* it is expensive
* it must be placed in a special condition, very cold room
Uses :
* To process huge amount of data
* To do processing transactions for large companies
* To process huge volume data needed to produce weather forecast, etc. - Personal Computer / Desktop computers:
Designed to used in one place
Advantage:
* They have better specification
* Keyboard is separated from the screen, so both can be adjusted
* They are cheaper to buy and repair
* Keyboard and mouse is easier to compare with the keyboard and mouse of laptop
Disadvantage:
* They are not PORTABLE
* Lots of wire that should be disconnected when moving the computer
* We need to spend time copying our files onto removable media.
