Orphaned and stale blocks

For any block in the chain, there is only one path (black blocks) it can have to the genesis block; that is, block #0 (green block), and the blocks in the smaller chain are eventually rejected. These valid blocks are known as orphaned blocks (red blocks) and are not part of the main chain. The transactions that exist within the rejected block(s) are re-added to the pool of queued transactions, and they will eventually be included in another block. With cryptocurrency blockchains, the reward received for solving orphaned blocks is practically lost. When, at any moment, a block is finalized, or "solved," everyone else should stop working on that block and restart their work. If a peer continues to work after that point, the block is known as a stale block because it is working on old data and transactions, as demonstrated in the following diagram: