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-processor based hand carried device such as a tablet computer such as the IPad and Android 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.