Definitions
Watt is a noun that refers to the unit of power, equal to one joule per second.
Example
The light bulb uses 60 watts of power.
Example
The amplifier can produce up to 100 watts of sound.
What is a pronoun used to ask for information or to introduce a clause that defines or identifies something.
Example
What is your name?
Example
I don't know what you're talking about.
Tips To Remember the Differences
Here are a few tips to easily distinguish the difference between these words while keeping in mind the description we've provided:
To remember the difference between watt and what, you could associate watt with electricity or power, and what with asking questions or seeking information.
Remember this!
Remember, watt is a unit of power, while what is a pronoun used to ask for information.