Glossary
LMD-GHOST
Ethereum's fork-choice rule — picks the block whose ancestor subtree contains the most-recent attestations from the most validators, weighted by stake.
LMD-GHOST — Latest Message Driven, Greedy Heaviest Observed Sub-Tree — is the fork-choice rule Ethereum's beacon chain uses to pick a single canonical tip among competing branches. Each validator's most recent attestation counts as a vote; the rule walks the block tree picking the heaviest sub-tree at each level.
The "latest message" qualifier means only each validator's most recent vote matters — earlier votes are superseded. Combined with Casper FFG (which provides explicit finality), LMD-GHOST gives Ethereum its sub-finality block production with predictable canonicalization.