How do computers communicate?

In the world of humans, for communication to take place between two individuals, it is required that both sides know the language that they want to communicate in. Similarly, in the world of computers, whenever two computers try to communicate, they must support the communication protocol.

To better understand the communication process between two computers, let's examine the example of communication between two individuals. When two people meet and begin to communicate, the following activities take place:

1. Person A formulates his/her opinion in their mind and utters the words through their mouth.
2. The air then acts as the transmission medium which transfers the words from person A to person B.
3. The transmitted words reach the ears of person B, who then, through the center of knowledge, understands the received words.

This works in almost the same way the communication between two computers occurs:

1. On computer A, an email has been compiled, and when the user clicks the send button, the mail application sends that message out through the computer’s network interface.
2. Depending on which connection the computer is using, it is either cable or wireless medium that will transmit the message to the central device (hub or switch).
3. The central device then forwards the message to computer B.
4. The received message by the network interface in computer B is then forwarded through its operating system to the mail application.