1_comper sience rvison

1_comper sience rvison

1. what is a computer system

   • Computers today are all around us in one shape or another. Whilst you are reading this page - how many computers are you aware of in the room? Maybe you are in a classroom right now and and you are near to a:
   • Mobile phone Calculator Watch Interactive white board Projector Printer Desktop computer Laptop
   • And more probably. The point is, that computers come in all shapes and sizes and are often built into other devices. But they share some common features. This mini-web will introduce you to a computer system.

2. types of hardware

   • ) Define the terms input device, output device, processing device, storage device and communications device ii) Define the term, peripheral iii) State and justify whether a device is an input, output, processing, storage or communications device

3. types of software

   • A computer is an electronic machine that can process data. But it needs to be told what to do in the form of a set of instructions. These instructions are called a 'software program'. Software allows the hardware to do something useful; without software, the hardware wouldn't know what it was supposed to do. So software depends on hardware and hardware depends on software. Together they form a computer system. Software programs are stored as files on a storage device such as the hard disk, DVD or memory sticks. When they need to run, they are loaded into the computer's memory (RAM). Use the menu on the left-hand side to find out more about the different categories of software.

4. computer systems in the modern world

   • We are surrounded by a multitude of computer systems in our every day lives. We rely on computer systems to keep us safe, to enable us to do our jobs, to entertain us, to run our homes and to enable us to communicate with other people. This mini-web will describe some of the uses that computer systems are put to.

5. Need for reliability in computer systems

   • We have come to depend on computer systems in terms of the services they provide and the data they hold. Therefore a key feature of a computer system is its reliability. This mini-web introduces the idea of reliability in computer systems.

6. units

   • Bits, bytes, kilobytes, megabytes, gigabytes and terabytes are all used to describe disk space, data storage or the capacity of system memory. You need to be able to define each of these different sizes and to place them into the correct order from smallest to largest. It would also be a good idea to be able to identify the most suitable storage capacity for a given scenario.