Materialized View
In plain terms
A precomputed, stored result of a query.
Going deeper
A materialized view caches a query's output physically, so expensive aggregations are read instantly instead of recomputed. It must be refreshed to stay current.
Under the hood
Trades freshness/storage for read speed; refresh strategies (on-demand, scheduled) manage staleness.
Examples
Dashboards, expensive aggregations, reporting, BI, summary tables.
Think of it like...
Like a saved report you print once and reuse, refreshing only periodically.