Hi Boeboe, most if not all of the information you are asking for is on the forum, there is a search function at the top of each page and you can type in keywords like feedhorn to get your answers.
Don't get me wrong, nobody minds answering questions, but not a relentless string of them.
PS. The actuator moves the dish and the feedhorn collects the signal from the dish, when attached to an LNB.