What is articulation?

articulation

Glossary “articulation” Definition:
1). The action of a chain joint in flexing from the straight to an angle and back to the straight as the joint passes around a sprocket or other path. 2). Vertical movement of the front driving or rear axle, relative to the frame of the vehicle to which they are attached. 3). Movement of the tie-rod end as the suspension moves through its range of travel.