Kinematics is the study of motion through position, velocity, and acceleration. It introduces the concept of an ideal particle with no size, internal structure, or mass that moves along a wordline. Speed is defined as the distance traveled over time and depends on the frame of reference. Average velocity is calculated as the change in position over a time interval, while instantaneous velocity provides the velocity exactly at a point by measuring over an infinitesimally small interval of time approaching that point.