The answer seems easy, since all of us are related to the terms, due to the use of our e-mail services. Basically, it sounds like the action of re-sending a message (e-mail) that was received in a specific e-mail address to a different one.
In this context, forward means that an e-mail has been pushed forward to different or more destinations besides the original.
But e-mail forwarding is not that, and it’s not as basic as it sounds. It has much more to offer you.