Explain the concept of denormalization in databases and why it is used.

Denormalization is the process of intentionally introducing redundancy into a database structure, that is, data duplication to speed up read operations. Unlike normalization, which aims to minimize repetitive data and dependencies, denormalization simplifies queries and reduces the number of table joins, thereby increasing performance during data retrieval.

Denormalization is used when read speed and system responsiveness are critical, such as in analytical systems or systems with a high volume of read requests, where the overhead of joining tables is too high. However, it increases the complexity of data maintenance, as it requires ensuring the consistency of duplicated information.