Electronic mail and Webmail

Electronic mail noun - (computer science) a system of world-wide electronic communication in which a computer user can compose a message at one terminal that can be regenerated at the recipient's terminal when the recipient logs in.

Webmail and electronic mail are semantically related. In some cases you can use "Webmail" instead a noun phrase "Electronic mail".

Electronic mail and webmail are semantically related. You can use "Electronic mail" instead a noun "Webmail".