Resistance Body :
A body is said to be resistance body if it is capable to Transmitting the required force with negligible deformation. It is the theoretical concept which is accepted.
Rigid Body :
A body is said to be rigid body if it is not subjected to any deformation under the application of force. It is the theoretical concept which is accepted.
Link :
A link or element is that part of a machine which has a relative motion to some other parts. It is a resistance body or assembly of resistant connected in such a way that they form a single part of it having no relative motion.
