Was wondering if it was possible to do globe artichokes in raised beds? If so, what would the depth of the beds need to be?

Also I've found stuff about growing artichokes that says it's a perennial; is this referring to the vegetable, and if so what does it mean?

I found an annual variety of globe artichoke called imperial star. Would I be able to harvest it the first year it's planted?

Do artichokes require an overwintering period like some other vegetables?