1. It consists of both a physical programmable development board (based on AVR series of microcontrollers) and a piece of software or IDE which runs on your computer and used to write and upload the code to the microcontroller board.
2. the language is C++
3. some projects you can do are:
3.1. Arduino Based Digital Ammeter
3.2. arduino metal detector
3.3. arduino relay control
4. Arduino is an open-source electronics platform based on easy-to-use hardware and software.
