I basically understand the principles of a blockchain, nodes and miners. I also basically understand how transactions are hashed/calculated to be added to the chain but i doesnt understand the dezentralized part.
For example bitcoin has a huge amount of nodes so its impossible to be connected to all nodes. Is there some kind of connection broker, root node thats always online or broadcasting that holds a list of nodes?
If a transaction is sucessfully hashed and published, how does it reach all nodes so that nobody will work on an already added transaction because he think its not finished yet? Ii think in some businesses its like on the wall street to fight about milliseconds.