And thinking of it in relation to computer commands, a la Star Trek:

{Speech Act, Illocutionary Act}

Following the usage of, for example, John R. Searle, “speech act” is often meant to refer just to the same thing as the term illocutionary act, which John L. Austin had originally introduced in How to Do Things with Words (published posthumously in 1962).

According to Austin’s preliminary informal description, the idea of an “illocutionary act” can be captured by emphasising that “by saying something, we do something”, as when a minister joins two people in marriage saying, “I now pronounce you husband and wife.” (Austin would eventually define the “illocutionary act” in a more exact manner.)

I’ve always understood this as essentially being what the “Amen” in conclusion of a prayer is for, meaning roughly, “Make it so,” to quote Capt. Picard. I think I have some more esoteric explanations of this somewhere or other.