With the help of digitizer, various graphs , maps , house designs etc. can be easily input into computer. The digitizer has a rectangular flat block called a digitizer board. It can range in size from 9 × 12 inches to 48 × 72 inches. Inside the board is a suitable electrical system. Anything that can be written or drawn on the board with the help of a stylus ( like a stylus pen) floats on the monitor screen. At the same time the position of the stylus at different times goes to the computer memory. A graph or picture drawn on a piece of paper can be placed on a digitizer board, turned on a stylus on that graph or picture, displayed on a screen, and its coordinates can be collected on a computer. Handwriting and menus , icons or buttons can be activated with a stylus pen.