Dividing a blockchain into pieces (shards) in order to reduce latency and speed up transaction processing. For example, the Ethereum 2.0 blockchain was designed to eventually be split into 64 shards to handle 64 times the workload. Instead of all nodes dealing with the same copy of the blockchain in a non-sharded environment, every node in a sharded network works on only one shard. See Ethereum 2.0
On September 15, 2022, Ethereum made a dramatic change. When the new network later splits into shards, the blockchain will be able to handle a huge increase in transactions every second.