Email client is a desktop application that enables configuring one or more email addresses to receive, read, compose and send emails from that email address(s) through the desktop interface. It provides a central interface for receiving, composing and sending emails of configured email address(s). We are basically using a "webmail" when we access Gmail, YahooMail etc. on our web browsers.
If you are looking for free email clients to use Gmail with, then Mozilla Thunderbird is a very popular and free open source email client. Thunderbird is a very popular Outlook replacement email client. In this post, we will see how to setup Gmail on Mozilla Thunderbird email client.