Email, shortened from “electronic mail”, is one of the most used methods of communication. Being one of the major components of the internet, it allows the sending and receiving of messages to other people, no matter where they are. Originally, email only supporting plain text messages, but as rich text and HTML developed, they became a integral part of sending emails. Now, most email services and servers support rich text, along with HTML and CSS that make emails look much more professional and appealing.
Email uses a specific set of protocols within the TCP/IP standard. These include SMTP (Simple Mail Transfer Protocol), POP (Post Office Protocol), and IMAP (Internet Message Access Protocol). While POP was used significantly in the past, many email clients, especially those which are web-based, are using IMAP. (Learn more about the differences between IMAP vs POP)
Receiving and sending emails also requires an email client. While the popularity of online email clients like Gmail has skyrocketed, desktop email clients like Microsoft Outlook and Apple Mail are still prominent, especially in the business space.