How many amps for a 220V?

Excuse me, could you possibly clarify something for me? I'm trying to understand the electrical requirements for a 220V system, and I'm wondering about the amperage involved. Specifically, how many amps would be necessary to power a 220V system? I'm aware that voltage and amperage are related, but I'm not entirely sure how to calculate the required amperage for a given voltage. Could you possibly enlighten me on this matter? Thank you for your time and assistance.