This document provides an overview of email including what it is, how it works, different email account types, differences between electronic and postal mail, usage of email, and etiquette for email communication. It defines email as an electronic message sent over the World Wide Web that allows users to send messages between computers. It describes the basic process of how an email is composed, sent to a service provider, and delivered to the recipient's inbox. It also discusses popular email services like Gmail, Yahoo, and MSN, and how email has become a key communication tool in business. Potential issues with excessive email usage are outlined as well as guidelines for proper "netiquette."