This is a quote from the book "Bitcoin: A Peer-to-Peer Electronic Cash System" by Satoshi Nakamoto
...the next proof-of-work is found and one branch becomes longer; the nodes that were working on the other branch will then switch to the longer one.
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New transaction broadcasts do not
necessarily need to reach all nodes. As long as they reach many nodes, they will get into a block before long. Block broadcasts are also tolerant of dropped messages. If a node does not receive
a block, it will request it when it receives the next block and realizes it missed one.
By convention, the first transaction in a block is a special transa...