Another commenter linked to a discussion about updating the Bitcoin software, but are you talking about updates to the Bitcoin blockchain? An 'update' would be

Another commenter linked to a discussion about updating the Bitcoin software, but are you talking about updates to the Bitcoin blockchain? An 'update' would be a new block or transaction. The Bitcoin network shares new blocks and transaction over a flood network where every node is peered with 8+ other nodes, and will tell all of them when it sees a new block or transaction.