Hi @designer, Annual one is automatically renewed, so you put the card there, and the subscription provider will automatically charge your card after a year. But if you don't want to think about the renewal and want to use Windy Premium only for a year, the One-year option is the right one for you.
According to question from @mjmatthews, I see that you purchased Windy Annual plan with automatic auto renewal two days ago, is it correct?