What is a Camera Tripod Head?
A camera tripod head is the part of a tripod system which attaches the camera to the tripod legs, allowing the camera to be fixed in a specific orientation.

How does a Camera Tripod Head Work?
A camera tripod head works by replacing the need of hand-holding the camera, allowing you to have much more control of the camera and thus, reducing vibration, quickly recompose for another shot, or allowing for long exposure photography.

Camera Tripod Quick Release Systems
Many tripod heads come with a quick-release system that allows you to attach your camera in a snap, reducing the possibility of dropping expensive cameras and lenses, and greatly reducing the time for screwing a camera directly onto a tripod head. A good example of quick release system is VEO's 235AB tripod system with Arca Swiss Quick Plate.

Five Types of Camera Tripod Heads
Tripod heads come in a variety sizes, weights and designs to suit different types of photography and equipment. Typically, the heavier the tripod head, the easier it is to have the tripod head stay put without allowing the camera to shift positions. The main types of tripod heads are as follows:
Pan-Tilt Tripod Heads
The Pan-Tilt (a.k.a. Three-way) tripod head is the most popular type of tripod head as it provides separate controls for panning left, right, tilting up and down, and rotating your camera for vertical compositions. The reason for pan-tilt tripod heads popularity is because they allow for precise control over individual motions.

Tripod Ball Heads
The tripod ballhead allows for quick rotational movement between panning and tilting, so camera positioning on the tripod is much more like the motions you'd use when hand-holding the camera.

Tripod Offset Ball Heads
The tripod offset ballhead allows for even greater rotational movement than the traditional tripod ballhead by giving you the ability to swing the camera platform through a complete circle. Because of their flexibility, tripod offset ballheads compliment very well pan-tilt tripod heads when used for shooting in overlooks.

Tripod Gimbal Heads
The tripod gimbal head is designed especially for large telephoto lenses which have built-in tripod mounts. The gimbal head supports the camera and lens firmly, but allows you to aim at will, without difficult locking mechanisms. The tripod gimbal head allows for almost unrestricted range of pans and tilts if the telephoto lens has a rotational mount collar. If your telephoto lens doesn't have a rotating collar, you can always use an L-bracket.

Tripod Fluid Heads
The tripod fluid head resembles pan-tilt heads and offers ultra-smooth pan and tilt movements similar to a tripod gimbal head, though a tripod fluid head doesn't offer rotation for vertical shots. The tripod fluid head is mostly used for motion picture, video work, and by photographers with long lenses.