What do you understand by the instantaneous center of rotation in kinematics of machines?

The instantaneous center of rotation (ICR) in kinematics refers to a point in a moving body where, at a specific instant, the body appears to rotate about that point. For any rigid body in motion, the ICR can change over time as the body moves. It is particularly useful in analyzing the motion of linkages in mechanisms, as it simplifies the analysis of their movement by allowing the use of rotational motion concepts. The location of the ICR can be determined by the intersection of the velocities of points on the body.