Sharding
The horizontal distribution of a data set across independent database nodes or partitions using an application-visible placement rule.
Database Context
Sharding horizontally distributes records across independent database nodes using an application-visible placement rule. The shard key shapes locality, query fan-out, hotspot risk, resharding cost, global-index design, and the difficulty of cross-shard transactions.
Distribution Boundary
The term overlaps with partitioning, but sharding usually emphasizes horizontal distribution across independently managed nodes rather than subdivisions within one database instance.