Sharding

Sharding is a scalability technique that splits a blockchain into parallel partitions, called shards, so each validator processes and stores only part of the network's workload instead of every transaction. Borrowed from database design, it aims to raise total capacity roughly in proportion to the number of shards while keeping the hardware demands on a single node modest, which helps preserve decentralisation. The hard parts are cross-shard communication — a transaction touching two shards needs a safe protocol between them — and security, because each shard is defended by a fraction of the validator set and therefore needs validators randomly assigned and regularly rotated. Some networks have shifted toward data sharding, where shards carry data availability for rollups rather than executing transactions themselves.