A slightly movable joint, which is the point where bones connect, is a joint that allows for limited mobility. These types of joints are called amphiarthrotic joints and include the intervertebral disc. Fibrous connective tissues or a layer of cartilage separates the bones that form amphiarthrotic joints.
Joints can be classified on the basis of structure or function. Structural classification deals with the manner in which the bones are connected, while functional classification has to do with the range of motion that a joint allows.
Amphiarthrosis is a functional joint class. The other two are synarthrosis, which allows for restricted or no mobility, and diarthrosis, which permits free mobility.