A vertical computer cabinet. A common design for servers and high-performance workstations, tower cases have more room for storage and card expansion than horizontal desktop cases and all-in-ones. In order to fit on shelves and equipment racks next to A/V equipment, home theater PCs (HTPCs) are housed in horizontal cases. All-in-ones are computers built into the monitor case and have the least internal flexibility. See all-in-one and HTPC.