A more thorough explanation:

Definition: E-mail is a way for people to communicate with each other using computers. It can be sent through a local area network or the Internet.

Example 1: John sent an e-mail to his boss to ask for a day off.

Example 2: Sarah received an e-mail from her friend with pictures from their vacation.

These examples illustrate how e-mail is used to exchange messages and information between people using computers. It is a convenient and fast way to communicate, especially when people are not in the same location.