Arduino is an open source platform used for building electronics projects. Arduino consists of both a physical programmable circuit board or microcontroller and a software, IDE (Integrated Development Environment) that runs on the computer. It is used to write and upload computer code to the physical board. Arduino board designs use a variety of microprocessors and controllers. The boards are equipped with sets of digital and analog input/output pins, USB connection which is used for loading programs from computers, power jack, reset button etc. A program written with the IDE for Arduino is called a sketch. The Arduino IDE supports the languages C and C++ using special rules of code structuring. It consists of only two functions, setup and loop. The setup function is used to initialize variables, input and output pin modes and other libraries needed in the sketch. After setup has been called, function loop is executed repeatedly in the main program. It controls the board until the board is powered off or reset. Arduino can interact with buttons, LEDs, motors, speakers, cameras, TV and smart phones etc. It can used for almost any electronics projects. The Arduino Tutorial effort for Arduino has been contributed by Prof. D DZala.