A breadstick as the name implys is simply a stick of bread. It is usaully known to be with pizza mainly. It can also have seasoning on it, like at Pizza Hut. Though it isn't always eaten with pizza as breadsticks are sold at Olive Garden which is in fact a italian resteraunt even though it isn't known for it's pizza much. Breadsticks can also be sold at american resteraunts like Max & Erma's, which doesn't sell pizza.

Pizza huts bread sticks have cheese and seasoning on them