The bag has one large main compartment with one big horizontal zippered pocket, 2 medium-sized vertical pockets, and one large one at the bottom for notebooks or a tablet. It has enough room for a few marble notebooks actually. This compartment looks pretty small but it expands to fit more of whatever you need to carry. Right now I have a large towel, face cloth, pair of pants, 3 pairs of socks, 3 t-shirts, and my north face raincoat rolled up in there, along with 3 books in the large pocket, toiletries in the zippered pocket, and some smaller stuff like a lighter, stash box, etc in the 2 smaller ones. It fits quite a bit.