Explain the concept of denormalization in databases and what it entails.

Denormalization is the process of intentionally duplicating data in a database to improve query performance.

In a normalized database, data is stored in multiple related tables, minimizing redundancy and ensuring integrity. However, complex queries with multiple joins (JOIN) can slow down performance.

Denormalization involves copying some data from related tables into a single table to reduce the number of JOINs and speed up read operations. This increases query speed but also enlarges the stored data volume and complicates updates, as consistency of duplicated data must be maintained.

Example: instead of storing the customer's name only in the customers table, it can be added to the orders table so that when fetching orders, a JOIN with customers is not necessary.

Thus, denormalization is a compromise between read speed and data maintenance complexity.