Arduino is a microcontroller family that can easily be programmed with a processing-like IDE. Its main features are:
- stand-alone operation
- programmable in a C-like language
- huge user-base, so lots of info/code/libraries available
- inputs (eg. for sensors or switches)
- outputs (eg. for LEDs, motors or to control other hardware)
- serial communication (RS232), via USB
- various shields available (eg. Bluetooth, XBee, WiFi, Network)
- REDIRECT
Get more information:
- Crash Course Programming for Arduino
- Arduino/Links
- If you are looking for Interface boards see this List for Alternatives: Interfaces#I/O Boards