A condyle is an ellipsoid knob of bone, which fits into a corresponding socket of another bone, the condyle and its socket forming a type of joint, called a condyloid joint, allowing movement in one or two planes but has no rotation. For example, the mandibular condyle is the condyle of the ramus of the mandible that articulates with the skull; the occipital condyle is a protrusion on the occipital bone of the skull that forms a joint with the first cervical vertebra (the atlas), enabling the head to move relative to the neck.