Cat6 is a twisted-pair copper cable rated for gigabit links across 100 meters and for 10 gigabit at shorter distances. It is the usual cable for IP cameras and Power over Ethernet, because it carries data and power together. The category is a minimum, and installation quality decides whether a run performs.
Cable is the part of a camera system that is hardest to change later. It is also where many intermittent faults live, long after the installer has left.
Cat6 in a camera system
One cable carries the video stream and the power, up to the 100-meter limit for copper Ethernet. Keep runs away from mains wiring, terminate to the correct standard and test every link. A cable that passes a continuity check can still fail at gigabit speed if a pair is miswired.
Cat6, Cat6a and shielding
Cat6a extends 10 gigabit across the full 100 meters and is bulkier and stiffer. Shielded cable helps in electrically noisy plant rooms, but it needs proper grounding at both ends to do anything. For camera work at gigabit speed, unshielded Cat6 is often sufficient.