What is Ardunio ??

Ardunio is device that allow us to control electrical appliances through our computer & smart phones .we can control any electrical appliance through ardunio .
There are many sort of ardunios Like.
1 : Ardunio UNO

2: Ardunio mega

3: Ardunio nano
![device20_1000_1.jpg] #fig source google ()
4: Ardunio leonardo

and any others etc.