Please clarify your question. "Diffence between ac volt?" is not a complete sentence and it's unclear what you're asking about.

To help you get the information you need, please provide more context. For example:

* What are you comparing AC voltage to? DC voltage? Another type of AC voltage?

* What aspects of AC voltage are you interested in? Frequency? Amplitude? RMS value?

* What specific question do you have about AC voltage?

Once you provide more detail, I can give you a helpful and accurate answer.