Acceleration refers to the change in velocity of a moving object within a certain period of time, either to a slower or faster pace, while deceleration exclusively refers to the negative acceleration (or slowing down) of an object. In layman's terms, acceleration usually only refers to positive acceleration.
Acceleration and deceleration are both represented by meters per second squared, which is also known as meters per second per second. These quantities also apply to nonlinear speeds, such as circular and sideways motions, and are often used in aeronautics, the automotive industry and other fields in which speed plays an important role.
