A screen capture is something that you use on your computer. What it does is records anything that is up on your screen. This includes everything from menus to your desktop.
It will save anything that you want to save off of your computer. If you want everything that is up on the monitor it will save it into a WMV file or an AVI video file. If you only want to just record a single application it can do that also.
The screen capture is also used to save audio off of your entire computer. For example if you want to save a conversation that you are having with someone. You can record both what you are saying and what is coming through the speakers. Everything that you save on screen capture will be put on a file. It can also record your web cam. When you are talking to someone and using web cam. It will record the person you are talking to along with your own images.
You can also use screen capture to record movies off the internet. You can record the whole movie or just certain scenes if you want. This is great if you just want to use a certain scene to use with a project or something. You can just save an image from a movie and add your own script with screen capture also.
A lot of teachers and such use screen capture to teach with. They can go through the internet and just record bits and pieces of different material that they need to teach on a subject. People also use screen capture for business purpose, for example for presentations. They can record just what they need to get their point across without gathering a lot of pointless information.
Another neat thing that screen capture can do is take you r files of pictures and make a movie out of it. To get screen capture on your computer all you have to do is download it. Sometimes they will give you a free trial then you will have to pay for it. But as you can see it does so much that it will be well worth it.