A verb is an action word. It describes the action of a noun or a pronoun.
Examples:
That is a peacock.
It can fly.
It can dance.
It can hop.
The words fly, dance, and hop describe what the peacock can do. These are action words for the peacock.
Vikram has a cat.
It can walk.
It can run.
It can climb.
The words walk, run, and climb describe what the cat can do. These are action words for the cat.