How to identify periodic and non periodic motion.

A periodic motion is defined as one that repeats itself after predetermined intervals of time, whereas a non-periodic motion is described as one that does not repeat itself after fixed intervals of time.

The earth, for example, revolves around the sun every 365 days and rotates once every 24 hours.

All planets move in a periodical pattern.

Pendulum of the clock

Non-periodic occurrences, on the other hand, occur at random and have no predetermined time after which they may occur again.

A shark hunting a little fish moves in a random and non-periodic manner. The shark and the fish do not repeat their movements at regular intervals.

Motion of time taken to reach school.

Hence, periodic motion can be identified by motions that repeat periodically and non periodic motion is the motion that does not repeat periodically.