How to create a new currency?

Hi, I just started using this platform for my website. But now I'm having some trouble not knowing how to create a new currency in the admin page. As the picture below, I don't know what the above values are and how to set them. Can anyone help me?

Sorry the forum doesn't allow newbie to add pictures :(

Prefix and suffix is used if your currency has special stmbols like $,€,£,¥.

Value means exchange rate with default currency.

Decimals means decimals :) 0 would show price like this - 12, 1 - 12.0, 2 - 12.05.