The tripod is the standard camera support. It has three legs, and (usually) a 1/4" screw to securely mount the camera to the top. Some tripods include non-removable heads, others are sold without heads.
Tripod Heads
2-Way Head
A 2-way head moves on 2 axis; this design is older but is still often used in sports photography or by others using long, heavy lenses.
3-Way Head
A 3-way head moves on 3 axis, allowing the camera to be placed in just about any position releative to the tripod.
Ball Head
A ball head is a tripod head based around a ball. Losening a tension knob usually allows the photographer to possition the camera anywhere they want. Tightening the same knob locks the camera's position.
Fluid Head
Fluid heads are designed to dampen sudden movements for smooth panning. Though occasionally used by still photographers in sports and action photography, fluid heads are most often used in video production.
Tripod Alternatives
Monopod
A monopod might be described as a one-legged tripod. It's a camera mount on top of a telescoping pole. Monopods are favored for light weight and portability, but they are not as sturdy as tripods.