• A 20x4 LCD means it can display 20 characters per line and there are 4 such lines.
• In this LCD each character is displayed in 5x7 pixel matrix.JHD204A
• Connection port is 0.1" pitch, single row for easy bread boarding and wiring
• Pins are documented on the back of the LCD to assist in wiring it up

This is a popular 20x4 LCD display. It is based on the HD44870 display controller hence it is easy to interface with most micro controllers.

It works of 5V and has a Green Back-light which can be switched on and off as desired. The contrast of the screen can also be controlled by varying the voltage at the contrast control pin(Pin 3).