The "mailto" link is a simple way to create a hyperlink that opens the user's default email client to send an email. When a user clicks on a "mailto" link, it automatically populates the recipient's email address, subject line, and even the body of the email if specified. This feature is commonly used on websites to make it easy for visitors to contact someone directly via email. To create a "mailto" link, you use the format: `mailto:email@example.com?subject=Your Subject&body=Your Message`. This allows for customization, making it convenient for users to reach out without manually entering the email details. It is widely supported across various web browsers and email clients.