Simple definition of Canonical Chain
- Canonical chain is the chain which is agreed to be the 'main' chain and not one of the side-chains which end.
- In theory it is never 100% sure which chain is the canonical chain. In theory you could still revert block number 1 (or is it block 2 which is after genesis block) by continuing its side-chains with enough hashing power.
Sources on Cononical Chain