What is "Trailer"?

In the search button of limerwire there is a choice of "trailer" along with vhs movies, dvd's, and things of that nature. What exactly is it?
And also, what would I get if I chose "other"?. What media fie would fit under that?

I don't normally search video. But I can tell you a trailer is the xtra bit of video at the end of a dvd. It might be a short which was used to advertise the movie in theatrs & runs for a 2-3 of mins. Or it's about the making of the movie. Generally it's the first. A quick summary of the main movie.

I appreciate the input.
So I guess "Trailer" pretty much ain't worth a @%&* unless your some kind of movie nerd.
But what happens if I click "other"? I cannot imagine what kind of media file would fall under that categort given all the other options.

Good question! I can only think of perhaps two. Animation films. Home movies. Or perhaps training videos. Oh & what about episodes of tv programs. There could also be different types of documentories or arty stuff.

I appreciate your feed back buddy.
You did not give me some pecker head replies like some folks who will rename un-named.
Your a good samaritan!