A Sugar Daddy is usually described as an old Rich Guy who wants sexual actions with young Girls or occasionally Boys, often in their 20's and 30's. Sugar Daddies pay their targets large amounts of Money so that Daddy can have Sex with them, often by buying them giant gifts. While it is not always bad to be a sugar daddy, many use negative forces. For instance, some are already Married, therefore Cheating on their wives. The most common tools of seduction they use include Chocolate, cars, and sometimes a full home. This makes it so it's not obviously Prostitution. Not all people who date Women significantly younger are necessarily Sugar Daddies.
Other times a rich elderly Gentleman marries a much younger woman and she's just after his money. Since that's more acceptable than sex outside marriage those husbands aren't called Sugar Daddies. The wives are still being bought.