What are the similarities between intrinsic motivation and extrinsic motivation?

Here are definitions, one can find similarities just by reading them.

Intrinsic Motivation:

"The motivation or desire to do something based on the enjoyment of the behavior itself rather than relying on or requiring external reinforcement."

eg. doing a hobby that you like, or volunteering on your own accord

Extrinsic Motivation:

"The desire or push to perform a certain behavior based on the potential external rewards that may be received as a result."

eg. studying for a test in order to pass, going to work so you don't get fired, etc.