Well, after reading your reply I understand a little bit better how the system works, but I've not totally understood it all so I'm reading more information.
So, you've explained to me that the Bitcoin network is made of thousands of computer, each computer is called a node. These computers run a software that is compatible with the Bitcoin network. Ok, it would be like if someone wants to download a file from Torrent network. That person would need to run Torrent software or a software that is compatible with the Torrent network protocol.
I don't fully understand when you say... "When a node has new information". From what part that information is coming from?
Another question I've about the mechanism of finding the correct hash is...
How the mining software knows that it has created the winning hash? As far I know the mining software looks for the correct hash, but when the software knows that the last hash created is the correct/incorrect one?