A shield is an auxiliary board that typically attaches to an Arduino Uno compatible board via the headers on either side of the board. They allow the addition of new capabilities to the general purpose microcontroller board. Shields can allow for connection of high power DC motors, relays, sensors, WiFi communications and many other specialized functions.
Not all shields can be used at the same time and compatibility can vary to board other than the Uno like the Leonardo. Please check the documentation first.
This is the SparkFun Vernier Interface Shield, a simple add-on to give your Arduino the capability to interface with Vernier sensors. Attached to this interface shield are four British Telecom sockets (2 Analogue, 2 Digital) which all Vernier sensors use as connectors. More Details...
Unleash your Arduino! This shield allows you to interface Wixel wireless modules to your Arduino (and other compatible products), enabling simple wireless programming, debugging, and control using standard Arduino software. Wixel developers can also use this item as a Wixel prototyping board. More Details...