computers can be generally classified by type size and power as follows though there is considerable overlap :
1.mobile Computing Device
A class of very small, micro-processsor based hand carried device such as a tablet computer such as the Ipad and Anddroid devices or Smartphones such as the IPhone and Windows Mobile devices in addition to its microprocessor a mobile computing device has a tiny keyboard touchpad or touch screen for entering data a small high resolution screen for displaying information and a storage device such as an sd memory card for saving data
2.pc or personal computer
a small micro-processor based computer in addition to one or more microprocessors a personal computer has a keyboard
for entering data a monitor for displaying information and a storage device for saving data Some pcs are very small so
they can be carried
3.Workstation
a more powerful single-user computer a workstation is similar to a pc but it has more microprocessors faster and larger
data storage and higher-quality graphics usually used for some special application such as application development or computer graphics
4.server
a multi-user computer system designed to support hundreds of users simultaneously a server can have many processors
some more than 32
5.mainframe a very powerful multi-user computer capable of supporting many thousands of users and millions of transactions simultaneously
6.supercomputer an extremely fast computer that can perform hundreds of billions of instructions per second sometimes using a parallel processing architecture with hundreds or thousands of thousands of processors