An email address is a unique identifier used to send and receive messages over the internet. It typically consists of two main parts: the local part, which identifies the user, and the domain part, which indicates the email service provider. For example, in the address "user@example.com," "user" is the local part, and "example.com" is the domain. Email addresses are essential for communication in both personal and professional settings. They allow users to exchange messages, share files, and connect with others globally. Most email services also offer features like spam filtering, organization tools, and security measures to protect users' information.