Acceleration shows the changes in the magnitude and direction of velocity. It is a vector with a standard unit of meters per second squared.
Displacement, acceleration and velocity are all part of kinetics, which describes motion. Kinetics gives the accurate description of an object's position or change in its position. Displacement, which is a vector, refers to the distance between an object's initial point to its final point. Its standard unit is a meter. The rate and direction of an object's motion is shown by velocity. Velocity, which is a vector, has a standard unit of meter per second.
Vector is comprised of direction and magnitude. The term "scalar" merely concerns magnitude. For example, speed is a scalar while velocity is a vector.