What makes ShadowPlay different from Fraps is that it has a rolling record feature that allows you to save automatically as you play. You can manually save a specific time frame, be it a few minutes or 20 with a quick hotkey combination.
I think the best thing about ShadowPlay is that it doesn’t cripple your computer’s performance the way Fraps does. ShadowPlay compresses the data into H.264 video files that are much smaller and manageable than Fraps’ output. ShadowPlay’s files will be in the megabyte range rather than gigabyte for just a minute of recording. According to Kevin Evangelho at Forbes, ShadowPlay’s quality is much higher while keeping the file size acceptable and shareable.
If your computer can’t handle rigorous processing or rendering, you should look into ShadowPlay if you’re interested in recording your own gameplay.