Why is simple syrup used on cakes? newbie question.

to keep them moist is why I use it : )

To add a little flavor. I put rasperry liqueur in mine.

Generally simple syrup is used to keep cakes moist or add a flavor such as a liquor. When I went to culinary school we used simple syrup on every cake we made but my chefs were French and German and most all the cakes we made were very dry. If you have a moist cake there is really no need to use it.