BGP, or Border Gateway Protocol, is one of the most important protocols on the Internet and one without which we would not be able to send and receive data. Simply put, BGP allows data to be routed over the Internet.
The BGP protocol is responsible for picking the shortest and fastest route so that your communication can be as smooth and efficient as possible.
Think of BGP as a postal service and individual Autonomous Systems ( AS) as post offices. Let's say, for instance, that you want to send data from the US (AS1) to someone in Japan (AS3). BGP will pick up the best route for you, which in this case might be AS1 > AS2 > AS3, instead of, say, AS1 > AS6 > AS5 > AS4 > AS3.