The main difference lies in their form. Simple syrup is in liquid form, while regular sugar is in granulated form. Dissolving regular sugar, especially in cold or iced drinks can be quite a hassle because it takes time and effort to fully dissolve the sugar crystals. This is where simple syrup comes in handy - because it's already in liquid form, it dissolves easily and quickly in any beverage. So, you don't have to worry about those pesky sugar crystals anymore!