What is a "screen capture"
A "screen capture" is where you can take a picture of what is on the computer screen. Then you can use that picture to show what you are seeing on the screen. There are a few ways to do a screenshot. Sometimes it works to hit control and printscreen to get a copy of what is on the screen. In the new version of Microsoft Office, you can open a Word document, and go to Insert & Screenshot. The different open windows will show up at the bottom and you can choose one to insert into your document.
It's a bit hard to explain without showing you. But let us know if you need further explanation.