Welcome to the forum. If you don't know the answer, there are no stupid questions.
Sounds like we have the same model “Stang”. First off find a reprint of the Ford Manual for our model. IF YOU ARE GOING TO WORK ON YOUR CAR YOU MUST HAVE THIS BOOK. There is a good explanation of the mechanical function as well as the Physics behind what is happening. Also, check out the Tech section of the Forum and order the Falcon Performance Manual. I just received mine and it’s worth $15.00 for what looks like years experience on this engine put together in one book. Until then, this is the place to get the answers to your questions.
Pills and Addo have the mechanical end of the choke covered. To get a feel of what is happening, remove your air cleaner and start your engine. Cup our hand and place it over the air horn of the carb until you start to feel the flow of air being “Pulled” into this air pump we call an Inline Six. The more you close your cupped hand around the air horn, the more you will feel your hand being “Sucked” down onto the carb. The same thing is happening when the Choke Plate is activated. This airflow is being “Choked” off and as a result the vacuum on the inside increases. Because of the way the carb works additional fuel is added to the air stream and “Richens” the mixture. This rich mixture is what helps the car start on those cold mornings.
Hope this helps, Ric.