The Hercules HD Twist has a maximum video resolution of 1280 x 720 pixels. That's over three times the video resolution of a 640 x 480 pixels webcam, which is the most frequently found video resolution.
This webcam's video resolution (1280 x 720 pixels) is actually the best video resolution amongst all webcams of a similar spec and age to the HD Twist.
Amongst similar types of webcam the worst video resolution is 640 x 480 pixels.
It may also be worth considering one of the alternative webcams that have a video resolution of 1280 x 720 pixels currently available including because of it's better review score, the V7 CS720A0 (£14.99).