How does Read Committed Snapshot Isolation differ from regular Read Committed isolation, and what tradeoff does enabling it introduce?

Read Committed Snapshot Isolation changes how the default Read Committed level behaves, using row versioning instead of shared locks for reads, which significantly reduces blocking between readers and writers, but introduces additional storage overhead in tempdb to maintain those row versions and a small amount of extra processing overhead for every data modification.

ALTER DATABASE MyDatabase SET READ_COMMITTED_SNAPSHOT ON;