Computer Hardware(Keyboard, Mouse, Printer,Monitor etc.):

Computer hardware's are  physical component of a computer system. It includes different parts like monitor, keyboard, and mouse etc. It contains physical parts related to the computer, like the hard disk drive,motherboard, video card, and many others. Computer hardware is what you can physically touch.

Computer hardware are as follows:
1. Monitor: It is a display unit or output unit of computer. It is a visual display unit(VDU). There mainly three types of monitors:
a. CRT Monitor: Cathode Ray Tube Monitor.
b. LED Monitor: Light Emitted Diode Monitor
c. LCD Monitor: Liquid Crystal Display Monitor

2. Keyboard: It is most common input device of computer.It is just like a typewriter. By using keyboard user can enter numbers, letters and different types symbols. There are different kinds of keyboards like laptops keyboard, video game keyboard and ergonomic keyboard.Keyboard has different types of keys like number keys, alphabet keys, symbol keys, editing keys, modifier keys, navigation key, lock keys, additional keys and function keys (F1 to F12). 
Caps lock key can be used to type capital letters continuously. 
Space bar key is used to give space.
Navigation keys are used to move left, right, up and down.
Editing keys are enter, delete and insert.

3. Mouse: It is a input device..There are different kinds of mouse available like optical mouse, wireless mouse, mechanical mouse, trackball mouse, two button mouse, three button mouse and scroll mouse.It can be used to perform many task like clicking, double clicking, open, close etc.

4. Printer: It is a output device.It can be divided into two categories-Impact and non-Impact printer.Impact printer also contain character printer and lines printer. Character printer is also contain Dot matrix printer.
Non-Impact printer include character printer and page printer.Character printer include ink-jet printer and page printer include laser printer.

5. Hard disk: It is a storage device of computer. Hard disk is a largest storage device of computer. It is also called a permanent memory because it stores data permanently. Today's external  hard drive also available.

6. Sound Card: It is a hardware that convert digital data into analog data. Most computer has inbuilt sound card. 

7. SMPS: It is a power supply device of computer. It is also known as power handling device.

8. DVD ROM: It is a device that is used for read a CD or DVD and write CD or DVD.

9. CPU: CPU control all the instructions given by input devices. It is also known as brain of computer. It perform different kinds of operations.It controls all parts of computer.It has memory, control unit and ALU.

10. RAM: Random Access Memory-It is a volatile memory so it can not store data permanently. 

11. VGA Card:Video Graphics Array. It has 15 pin connectors. Each pin has its own working.

12. CPU Fan: It is used for control heat insided CPU.

13. Speaker: It is output device.It convert electromagnetic waves into sound. Digital speakers convert digital signal into analog signal.
14. Pen Drive: It is a re-writable device.It is movable device. It is also known as flash drive.Currently available pen drives are 8 gb, 16 gb, 32 gb, 64 gb, 128 gb. To take data into pen drive we can plugged into  a USB port of compute.