What is the difference between case sizes?
Cases come in various shapes and sizes, but there are a few main categories that most desktop PC cases fit into.
Mid-sized towers are the most common PC cases for gamers and usually have 3-4 external expansion bays. They stand about 17 to 21 inches and can almost always hold a full size ATX motherboard while typically being able to handle two graphics cards with about 2-8 hard drive and SSD mounts.
Full towers can have 5 or more external bays and can range in height from 22 to 27 inches. They almost always support full size ATX and E-ATX motherboards. These cases also offer the most drive expansion options, provide better cooling for 3 or 4-way graphics configurations, and have more than enough space for the best custom liquid cooling setups.