Bitcoin information data protocol Obviously for the Bitcoin system to work, we need an information network on a global scale such as the Internet.

I am sorry if this is a stupid question.

What exact information protocol is being used? Obviously something that sits on top of TCP/IP, but what exactly?

It is these first levels of software that on top of TCP/IP that I am interested...
Bitcoin uses its own wire protocol, which is based on TCP. It's quite simple, with each packet type having strict rules for conformity and a checksum. New objects (transactions and blocks) are flooded through the network to all peers with a flag indicating they want that information, along with auxiliary messages like peer addresses and pings. No encryption is used for any connection. 

https://bitcoin.org/en/developer-reference#p2p-network