Today's keyboards offer many options, but they tend to fall into two basic categories: full-size and compact. A full-size keyboard is likely the size you know best. They have 104 keys, including a numpad on the right side. Anyone who spends a lot of time with numbers is likely to prefer the speed and ease of a numpad. Full-size keyboards can be uncomfortable for some, however, because they're wide. This pushes the mouse far to the side, increasing the movement needed to use the mouse.  Compact keyboards, also known as tenkeyless keyboards, ditch the numpad but retain the arrows keys and function keys above them. This cuts down keyboard size significantly without changing the day-to-day experience for those who don't often use a numpad. TKL keyboards free up desk space and keep your mouse close at hand, which some find more comfortable.  The ideal size is a personal preference. Smaller keyboards free up space and can be more ergonomic, but not everyone who uses a full-size keyboard finds them uncomfortable and some people prefer the functions found in additional keys.