Megapixels remain megapixels even for a DSLR. Megapixels define the resolution of the image, it is same for camera phones, compact cameras or DSLRs, but the range varies.
There are many things like shutter life span, maximum shutter speed, ISO range, etc but there are two things that will help you in picking the right gear: first is your budget and second is your level as a photographer. If you are just beginning, go in for any entry level DSLR. I think Nikon D3200 is a good option.
FPS or frames per second defines the camera’s ability to shoot multiple frames in continuous shooting mode. Higher the fps, higher is the number of shots captured per second. That shows the processing speed of the camera. You will basically need it while shooting action shots; because you cannot afford to miss the shot. I used it when I was trying to capture the water splash – dialed the shutter priority mode, chose the shutter-speed of 1/4000 sec (max that my camera allows), turned on the continuous shooting mode and yep, I was able to get a few good shots.
Hope this helps!!!!!