For starters, it's "software"

just saying.
Second, you really need a good computer to use FRAPS effectively. Low-end computers will suffer tremendously with FRAPS recording. Medium-range computers will have to tone the settings down a bit. If you have a really great computer, by all means, feel free. The same applies with laptops, except for the fact that high-end laptops may also need to tone settings down a bit depending on the game and laptop and the usual for medium and low-end.
FRAPS eats the living hell out of your processor, RAM, hard drive and GPU combined all together.
- Processor - Compresses the video if you set it to do so, records audio.
- RAM - Not so much as the others, but if you have a low amount of RAM (anything less than 4GB) you will have problems with decent framerate. I have 6GB, which is plenty.
- Hard drive - If your hard drive runs slower than 7200 RPM inside, you're going to have framerate problems because FRAPS pretty much records the screen and writes it to the hard drive. Solid states, although incredibly expensive now for large sized ones, will help you a LOT. You also need a lot of hard drive space, depending on how long you record for, the quality in framerate per second, and the size you are recording in (half size or full size, and your resolution).
- GPU - (graphics processing unit, makes pretty pictures) You need at least a medium-end GPU. Again, FRAPS records every single frame that your graphics card renders for whatever game. If you can't play the game on lowest settings at 20 FPS, you're going to have extreme difficulty getting a good clip out of that game. Plus, a high-end graphics card will let you play the game on the highest settings which in turn makes your video look nice because that's the prettiest the game can be.
All in all; powerful computer? don't worry. low-end computer? don't buy it. not sure? do research or don't buy it.