Palm ( Palm) means the computer that can be worked in the palm of the hand is called a palmtop computer. It is also called Personal Digital Assistant or PDA or Handheld or Pocket Computer. This model is the smallest of the various computer shaped models. In terms of power, it is much weaker than notebook or desktop computers. The work of some special applications can be done by it. These include working in a small spread on a spreadsheet , displaying the required address and telephone number , keeping notes of date and agenda. Some PDAs are designed to be integrated with large computers for data exchange. This branch of computer is now growing. With the development of PDA comes digital pen and touchscreen facility which means that various instructions can be given by stopping at the digital pen display. It also allows users to write. Due to its small size, it usually does not have a disk drive.