This book provides an up-to-date treatment of various aspects related to kinematics. It covers topics such as Euclidean displacements, instantaneous kinematics, theories involving multiple positions (two-position, three-position, and four-and-more position theory), special motions, multiparameter motions, and kinematics in different geometries. The book serves as an excellent reference for students and scholars involved in the field of kinematics of machines, dynamics of machines, machine design, and vibrations. Its primary purpose is to be used as a reference book for researchers exploring the intricacies of mechanisms' kinematics