forwarding vs transmitting

forwarding and transmitting both are nouns.

Word	Noun	Adjective	Verb	Adverb
forwarding	Yes	No	No	No
transmitting	Yes	No	No	No

As nouns, transmitting is a hypernym of forwarding; that is, transmitting is a word with a broader meaning than forwarding:

forwarding: the act of sending on to another destination
transmitting: the act of sending a message; causing a message to be transmitted

Other hypernyms of forwarding include transmission, transmittal.

forwarding (noun)	transmitting (noun)
the act of sending on to another destination	the act of sending a message; causing a message to be transmitted
the advancement of some enterprise