Digital Still Camera vs. Webcam

I'm still pretty new to all this, but I have been noticing a trend (I think). It seems that the most detailed images of planets that I see are the ones taken using video methods like the Toucams and such. Is it correct to say that if one is looking to produce the most detailed image possible, that the video methods using web cams are the way to go? Or can a digital still camera also produce images as detailed as from video? Are video images intrinsicly better resolution, or are they better simply because of the sheer number of frames captured you have higher chance of getting some that beat the seeing? My digital still images, even the ones I stack 20 pictures to obtain, are nowhere near as detailed as the webcam ones I have seen. And my telescope has at least diffraction limited optics or better. Thanks for any replies.