• When a miner finally comes up with a solution other nodes quickly check it (that’s the one-way street again: solving is hard but checking is easy), and each node that confirms the solution updates the blockchain .
• It is the concatenation that makes the blocks into a chain.
• The technology behind bitcoin could transform how the economy works
• And nodes always work on the longest version of the blockchain there is.
• As the proposal propagates over the network the various nodes check, by inspecting the ledger, whether Alice actually has the bitcoin she now wants to spend.

Read more