This list of computer size categories attempts to list commonly used categories of computer by size, in descending order of size. Of course, one generation's "supercomputer" is the next generation's "mainframe", and a "PDA" does not have the same set of functions as a "laptop", but the list should have some recognition value. It also ranks some more obscure computer sizes.
Main frame computer is a large,expensive,but powerful computer that can handle hundreds and thousands of connected users at the same time.
The classes above are not rigid; there are "edge devices" in most of them. For instance, the "subnotebook" category can usually be distinguished from the "PDA" category because a subnotebook has a keyboard and a PDA has not; however, tablet PCs may be larger than subnotebooks (making it seemingly correct to classify them as laptops) and also lack a keyboard, while devices such as the Handspring Treo 600 have something that might charitably be called a keyboard, but are still definitely in the "smartphone" category.
In the higher end of the spectrum, this informal rule might help:
- You can throw a laptop
- You can lift a workstation
- You can tilt a minicomputer
- You cannot move a mainframe