Electronic shelf label

An electronic shelf label (ESL) system is used by retailers for displaying, typically on the front edge of retail shelving, product pricing on shelves that can automatically be updated or changed under the control of a central server.^[1]

ESL tag modules use electronic paper (E-paper) or liquid-crystal display (LCD) to show the current product price to the customer. E-paper is widely used on ESLs as it provides crisp display and supports full graphic imaging while needing only power during updates, but no power to retain an image. A communication network from the central server allows the price display to be automatically updated whenever a product price is changed, in contrast to static placards. Wireless communication must support application range, speed, battery life, and reliability. The means of wireless communication can be based on radio, infrared or even visible light communication.^[2] Currently, the ESL market leans heavily towards radio frequency communication.^{[citation needed]}