What is the difference between normal views and materialized views?

A normal (standard) view is a virtual table defined by a SELECT statement. It does not store data; each time you query it, the database re‑executes the underlying query, which can be slow for complex joins. A materialized view, on the other hand, physically stores the result set of its query. It is refreshed either manually or on a schedule, so subsequent queries read from the pre‑computed data, resulting in faster query performance. The trade‑off is that materialized views consume storage and require maintenance to keep them up to date.