transform

Transformation comes from the word transform which means to change form.

For example:

The transformation from a baby to an adult takes many years for humans. For most animals, this transformation is much faster.

Some transformations are very quick, for example, when you burn a match it changes from wood to ashes.

People who start exercising and stop eating candy and cakes often achieve a complete physical transformation. Instead of being very fat, they become very thin.