All teeth of a person are arranged into two arches in the oral cavity. When both arches come closer together, contact between the opposing teeth is present. 

The upper arch is a fixated arch named the maxillary arch, while the lower arch is movable, and it is called the mandibular arch as the mandible forms it.

As the mandibular arch is movable, it operates against the maxillary arch and provides that the upper and lower teeth actually meet. The term occlusion is used when the upper and lower teeth are in actual contact. It is also known as the occlusal relationship. The occlusion is also referred to as the whole state of interarch teeth contact, but not to a single contact between specific teeth. 

When the misalignment or incorrect relation between the teeth of the upper and lower arches is present, it is known as malocclusion, but the teeth that are out of contact are known as being in disclusion. Malocclusion can have an impact on the formation of dental diseases, chewing, speech, and aesthetical look of a person. 

Static occlusion is the contact between mandibular and maxillary teeth when the lower jaw is not moving. Dynamic occlusion, on the other hand, is the contact that teeth form during the movements at the temporomandibular joint - when the lower jaw moves side to side, backward, forward, or at an angle.

In a static occlusion, contacts are described with points, while in dynamic - with lines.