Sharding is an approach to blockchain scalability, which partitions processing across multiple groups of nodes ('shards'). The design is inspired by traditional database sharding, which effectively breaks large data structures into smaller, more easily managed pieces. Blockchain sharding is a layer 1 approach to scalability whereby consensus is no longer requried globally, only locally amongst subsets of nodes. Sharding obviates the need for every node to process every transaction, whilst ensuring transaction validity across shards. A variety of smart contract platforms, most notably Ethereum, aim to utilize a form of sharding in their scalability approaches.