To start recording you have to either press the record button, or use the customizable keyboard shortcuts in the program. That said, before you do you have to set the parameters of your video, such as the area of the screen to record and the frame rate.
Once you finish the video, you have a few interesting options at hand: you can edit it, crop a section you're not interested in, and export it to either AVI or BMP (in a sequence of images).
DemoRec is a pretty useful tool for creating video tutorials. Thanks to its simplicity, anyone can start using it with no trouble.
Adds a watermark to the output video.