The physical computer and its components are known as hardware. The computer hardware is the part of a computer system that you can touch, see and feel. Computer hardware is divided into two main categories, i.e. System Unit and Peripherals.
The system unit is the electronic components such as the CPU, primary memory, and other data storage devices.
System unit components are:
- Floppy disk drive.
- CD-Rom/CD Writer/DVD Drive.
- Hard Disk Drive for storage purposes.
- Random Access Memory (RAM).
- CPU – Central Processing Unit (ALU, Control Unit and Register for storage).
- MotherBoard.
- Power Supply Unit.
A brief explanation of some of the components of the system unit is as follows:
1. The arithmetic and Logic Unit (ALU) is the part of the Central Processing Unit where the actual mathematical operations are carried out.
2. The Control Unit – On the other hand, coordinates all the activities that are carried out by the computer in sequential order.
The Memory Unit – there are two types of computer memory “Internal and External memory”. The computer’s internal memory is sub-divided into RAM and ROM, referred to as the computer’s primary, main, internal, or just memory.
i. RAM (Random Access Memory) – is meant to hold data ready for processing and data already processed but set to be printed, copied or saved. RAM also contains data or programs as long as the power is on. Otherwise, all data and information will be lost when the power fails, or you switch off the system.
In other words, RAM is temporary or volatile storage. RAM is the computer worksheet, which
means application programs and data are loaded on it from the external or secondary storage devices for processing. However, RAM is of limited capacity, and the computer’s ability to run a given application is determined by its RAM size.
ii. ROM (Read Only Memory) – as the name implies, ROM can only be read but cannot be written. Data is permanently stored (Hardware) inside this chip by the manufacturers. ROM is the store of programs or instructions that the computer needs at booting or collecting those instructions or programs that accomplish some utility functions of the computer. Whatever information is stored in ROM remains permanent even if there is a power failure or you shut off the system.
3. Central Processing Unit (CPU) – in computer science, microscopic circuitry serves as the main information processor in a computer. A CPU is generally a single microprocessor made from a wafer of semiconducting materials, usually silicon, with millions of electrical components on its surface. On a higher level, the CPU is many interconnected processing units responsible for one aspect of the CPU’s function.
Standard CPUs contain processing units that interpret and implement software instructions, perform calculations and comparisons, make logical decisions (determining if a statement is true or false based on the rules of Boolean algebra), temporarily store information for use by another of the CPU’s processing units, keep track of the current step in the execution of the program, and allow the CPU to communicate with the rest of the computer.