Explain how indexing works in a database and why it is important.

Indexing in a database involves creating data structures (indexes) that store a sorted list of values from one or more columns of a table, along with pointers to the corresponding rows. It is important because: 1. Faster Data Retrieval: Indexes allow the database to quickly locate the rows that match a query's search criteria, reducing the need for a full table scan. 2. Improved Query Performance: Indexes enable the database to use various search algorithms like binary search, significantly speeding up data retrieval. 3. Data Integrity: Indexes can enforce uniqueness and primary key constraints, ensuring data accuracy. However, it's important to note that while indexing improves read performance, it can slightly slow down write operations, so proper indexing strategies are essential for database optimization.