### Theory:

Change is constant. A process in which a substance becomes a different one from what it was earlier. The difference in the size or shape of an object is termed as 'change'.
Example:
Day turns to night, growing crops in the agricultural field, falling of leaves from trees, blooming of flowers, etc.
Types of changes based on periodicity: Changes are classified as periodic and non-periodic changes.

1. Periodic change: Periodic changes are changes that occur at regular intervals of time.
Periodic changes related to time

The below are some examples of periodic changes:

Occurrence of day and night:

The $$24$$ hours clock shows the difference in day and night, which is an example of periodic change.

Heartbeat:

The heartbeat for a minute is around $$60$$ to $$100$$ beats for an average person.

Clock bells every hour:

The alignment of the minute and hour needle of the clock for every hour and second is an example of periodic change.

Rotation and revolution of the earth:

The rotation in $$24$$ hours makes the changes in day and night on earth. The revolution of earth for $$365$$ days around the sun makes the changes in years.

Seasonal changes:

The changes in seasons such as summer, winter, spring, and monsoon are also examples of periodic changes.
2. Non-periodic change: Non-periodic changes occurs randomly without any time. Natural calamities are the best examples of these types of changes.
Non-periodic changes do not depend on the time

Here are some examples of non-periodic changes:

Eruption of a volcano:

The eruption of a volcano is an example of non-periodic change as it occurs unexpectedly and the reoccurrence is not in a timely manner.

Running of batsman between the wickets:

The running between the wickets is an example of non-periodic change as it depends on the batsman and the ball placement in the field.

Playing dodgeball:

In this game, the ball is thrown, and the person in the centre jumps randomly, which is an example of non-periodic change.

Dancing:

The movement of legs and hands in different steps are random and not in a periodic motion. Thus, dancing is an example of non-periodic motion.