Timechain is an early Bitcoin term for the chain of blocks. Each block commits to the previous block’s hash, creating an ordered record. Nodes select the valid chain with the most accumulated proof of work.
Bitcoin cannot give every transaction a perfect global timestamp. Blocks instead establish a defensible sequence: a transaction included in an earlier block existed before the proof of work for later blocks.
The rule is not simply the greatest number of blocks. Nodes follow the valid chain with the greatest cumulative chainwork, which matters when blocks have been mined under different difficulty targets.
For the clearest picture, read this entry together with Genesis Block, Proof of Work, Transaction, Full Node, Difficulty Adjustment. The reverse links also lead from Satoshi Nakamoto, Bitcoin Whitepaper, Genesis Block, Proof of Work.
Blocks commit to prior hashes
Orders history probabilistically
Chainwork matters, not block count alone
Every node validates independently