What is difference between periodic motion and oscillatory motion ?

Hi Aman!

 

Oscillatory motion refers to the motion in which the object moves back and forth repeatedly. While periodic motion refers to the motion in which the object repeats a path after a regular interval of time.

All oscillatory motion are periodic but all periodic motion are not oscillatory.

For example consider motion of Earth around the sun. A complete orbit takes roughly 365 days and therefore this is a periodic motion. However, cannot be said to be oscillatory. A motion of pendulum is both oscillatory as well as periodic.
 

Hope it is clear to you!

Good luck!