Each resistant body in a machine which moves relative to another resistant body is called Kinematic link or element. A resistant body is which do not go under deformation while transmitting the force.
Kinematic links can be divided into three types.
1. Rigid link- In this type of link there is no deformation while transmitting the motion. Motion between the piston and crank can be considered as a rigid link.
2. Flexible link- In this type of link there is partial deformation while transmitting the motion. Belt drive is an example of flexible link.
3. Fluid link- In this type of link the motion is transmitted with the help of fluid pressure. Hydraulic brake is an example of fluid link.