Email stands for electronic mail.
When someone sends a message electronically to another person through the Internet, it is stored in an electronic mailbox where the recipient fetches them. To see if you have any email, you can check your electronic mailbox periodically, although many programs can be configured to alert you automatically when mail is received. After reading your email, you can store it as a text file or delete it, reply to it or forward it to others, print it or create a new message. It's like an electronic mailbox or street address so that your computer knows where to get your email from. This is why POP servers are often called your incoming mail server.