Computer is an electronic machine that consists of number of interrelated components. Each of these components has their specific contribution to the functioning of a computer system.
Let’s look at definition and classification of computer devices along with some fundamental knowledge.
Define a computer
If we want to generalize the functionality of various computers on earth and want to define it in a single sentence then we may say –
Computer is a group of interconnected electronic machines, which takes input from user as instruction or data, process the data as per instruction and either stores the processed data or returns it in the desired format to the user.
Based on the above definition, a computer system performs the following operations:
- Takes data and/or instruction – input
- Process the data as per instruction – processing
- Stores the processed data in memory – storage
- Sends the processed data to user either as on screen copy (soft copy) or printed on a paper (hard copy)
What are the main parts of a computer?
The main parts of computer are:
- Monitor
- CPU
- Mouse
- Keyboard
Apart from these, there are some peripherals which can be voluntarily attached to computer for some additional features. These are:
- Printer
- Scanner
- Webcam
- Joystick
- UPS
Classification of computer devices
Based on their functionalities, the above mentioned devices are broadly classified into 4 types.
What are input devices?
The devices which are used to give instruction or send data to the CPU are called input devices.
Example:
Keyboard -> to input letters, numbers or symbols
Mouse -> to give instructions to the CPU by clicking on various commands on GUI based OS
Microphone -> to capture sounds and send to CPU like recording songs or speeches
Webcam -> to capture video or still picture and send to CPU
Joystick -> to send instruction to CPU while playing video games
What are processing devices?
CPU is the processing device in a computer which processes the input data based on instruction given by the input devices. After processing, the data is either send to output devices in the desired format or to storage devices.
What are output devices?
The devices which are used by CPU to send the processed data to user in the desired format are called output devices.
Example:
Monitor -> displays the soft copy of the data
Speaker -> to hear songs or speeches played by CPU
Printer -> to print output data on paper as hard copy
Projector -> to display the soft copy on a larger screen for larger audience
What are storage devices?
The computer uses data and software. So the computer needs devices to store them. Also at times we want the processed data to be stored for future reference. For this, the computer uses storage devices or memory devices.
The devices which are used to store information like data or software permanently or temporarily in electronic format are called storage devices.
Example: Hard disk, CD, DVD, Pen Drive etc.
Storage devices or memory devices are further classified into Primary memory and Secondary Memory.
Primary memories are classified into Random Access Memory (RAM) and Read Only Memory (ROM).
Secondary Memory includes Hard Disk, CD, DVD, Memory Card etc.
