The open-source Arduino Software integrated development environment (IDE) makes it easy to write code and upload it to the board. The Arduino IDE supports the C and C++ languages. Arduino IDE sketch require two basic function
1)setup :
The setup function is called when a sketch starts. Use it to initialize variables, pin modes, start using libraries, etc. The setup function will only run once, after each power up or reset of the Arduino board.
2)loop:
loop consecutively, allowing your program to change and respond.