WHAT IS ARDUINO UNO

Arduino is an open-source hardware and software company, project and user community that designs and manufactures single-board microcontrollers and microcontroller kits for building digital devices.

Please pay attention for 5V, GND, USB Plug and digital pins 0 -13...

It is connected to computer via USB Plug with this cable:

Bread board is used to creating the circuit:

You can see back of a breadboard how is connected.