Explanation

An email address consists of two parts: 

1. Username or ID (the name or ID chosen by the user)
2. Domain name (the name of the organization or service provider).

Format: Username@Domainname.com

Example: john.doe@example.com

Email, short for Electronic Mail, has its roots in the early 1960s.

The first email was sent in 1971 by Ray Tomlinson.

He also introduced the "@" symbol to separate the username from the hostname.