Computer components can be divided into two groups, hardware and software. Hardware is any part of a computer that you can touch. While there are thousands of components even on the smallest computers that make up its hardware, you don’t need to know them all. You only need to know about basic computer hardware.


Basic computer systems have the following components:

1. CPU (Central Processing Unit)

The CPU is considered a computer brain. Performs all types of data processing, saves data, intermediate results and commands (system). Controls the performance of all computer components. The CPU has 3 elements as listed below.

(A) CU (Control Unit)

The control unit (CU) is part of the central processing unit (CPU) of the computer that controls the operation of the processor. It tells computer memory, arithmetic logic unit and input and output objects how to respond to system commands. However, the Control Unit does not process any data.

(B) ALU (Arithmetic Logic Unit)

Think of ALU as a conscious part of the brain. Where any mathematical calculation or decision / concept needs to be performed, instructions are forwarded to the ALU. ALU thinks of bits (e.g. binary digits - '0's and' 1's.)

(C) Memory

The main memory is part of the computer itself and is required for its operation. It contains mainly two types of memories:

(i) Random Access Memory (RAM)

RAM is an internal memory CPU for data storage, system and system output. Read / write memory that stores data until the machine is activated. As soon as the machine is turned off, the data is erased. RAM does not change. Variable means that data stored in memory is lost when we turn off the computer or in case of power failure.

(ii) Read Only Memory (ROM)

The memory we can only read from but cannot write on. This type of memory is not static. Details are stored permanently in such memories during execution. ROM, keeps such commands needed to start the computer. This function is called bootstrap. Different types of ROMs are given below.


2. Second Storage (External Storage Devices)

Floppy diskettes, hard disks, tapes and disks fall under the category of external storage devices or auxiliary storage devices. These devices are highly sensitive to environmental conditions (humidity and temperature) as well as external magnetic field and require careful maintenance. It is not mandatory for computer performance but is useful for increasing computer memory.

(A) Floppy Disk

Floppy disks are widely used on PCs. The details on the floppy disk are recorded in the strong magnetic fields of iron oxides particles that are evenly placed in the fixed circles known as the tracks.

(B) Hard Disk

A removable magnetic disk that is removable is installed on most PCs. It consists of a number of layers of metal, each with iron oxide, which rotates on a spinning top and the entire unit is enclosed in a closed chamber.

(C) Magnetic Tape

This is plastic, usually made of Mylar coated with iron oxide, thus enabling the introduction (writing); storage (memory) and reading of recorded magnetic information. The best use of the step is for data that you do not use much.

(D) Optical Disc Drive

A compact disc (ODD) is a disk drive that uses laser light or electric waves to read or write data to or from the discs (usually CD-ROM). A CD-ROM is a compact compact disc that contains pre-contained information. This term is abbreviated to "Disk Read Only Memory". Computers can read CD-ROMs, but they cannot write on CD-ROMs that are not written or removable.

(E) USB

USB flash drive, also known as USB drive, USB stick and various other names. It is a data storage device that includes flash memory with a virtual USB connector. USB flash drives are usually removable and labeled, and are much smaller than a visible disc.

(3) Peripheral

Peripheral devices are devices connected to an external computer. If the peripheral device is disconnected, the computer will still be able to operate; functions performed only by this device will not be available. Here are the most commonly used types of peripheral devices:

(A) Keyboard

A common and popular input device that helps to enter data into a computer. It contains keys that can include letters, numbers and special characters. You can also navigate using the keyboard and perform shortcut tasks.


(B) The mouse

The mouse is a popular pointing device and a control device with a small palm-sized box and a round ball at its base that senses the mouse movement and sends the corresponding signals to the CPU when the mouse buttons are pressed.


(C) Monitors

Monitors, commonly referred to as Visual Display Unit (VDU), are a basic computer output tool. Create images from small dots, called rectangularly arranged pixels. Image sharpness depends on the number of pixels.


(D) Printer

Printer is a printing tool, used to print information on paper.

Impact Printers: Influential printers print characters by striking them on a paper-pressed bond.

Non-impact printers: Non-impact printers print characters without using a ribbon. These printers print out a complete page at the same time and are also called Page Prints. Laser Printers, Inkjet Printers.


(E) Joy Stick

It is a device used to move the cursor position to the monitoring screen. It is widely used in Computer Aided Designing (CAD) and computer gaming.


(F) Scanner

The scanner allows you to scan printed material and convert it into a file format that can be used within a PC.