So you need to get a screen shot of what you are doing. The old way (Windows 7 and previous) was CTRL+PrtScn then paste the image into Word, or some other text editing program. That's a bit limited as you may not want all the image, or you may want to edit out some personal information that happens to be on the page you need to grab. Now, introduce Windows 10 and the new screen grab tool. Just press Windows key+shift+S and low and behold you can now draw around the section of your screen you wish to grab. Now with a quick click of the windows Ink workspace icon, you have access to 'Screen Sketch' which then allows you to highlight, draw and crop your screen grab. Really useful if you need to send an annotated screen grab to someone.
There are additional features to this facility which are to be included in the next update - currently in testing by Windows Insiders. This includes a new button set when the Win Shift S are pressed that will give more flexibility. We'll probably have to wait until the autumn for these to arrive though.