Correspondence course and Email

Correspondence course noun - A course offered (by mail) by a correspondence school.

Email and correspondence course are semantically related. In some cases you can use "Email" instead a noun phrase "Correspondence course".

Email 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.

Correspondence course and email are semantically related. Sometimes you can replace phrase "Correspondence course" with "Email", this terms are similar.