01Definition
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.
02Ordering without a clock authority
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.
03Why “longest chain” is shorthand
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.
⌖Reference points
01
Blocks commit to prior hashes
02
Orders history probabilistically
03
Chainwork matters, not block count alone
04
Every node validates independently