In cloud computing, query optimization is the process of improving the speed and efficiency of data retrieval operations in a database. It's a crucial aspect of database management, especially in large-scale cloud environments where data retrieval operations can be complex and resource-intensive.

• Query optimization can significantly improve the performance of data retrieval operations.
• It involves rewriting queries, creating or modifying indexes, partitioning tables, or adjusting database parameters.

Query optimization works by improving the way queries are processed in a database.

• It involves analyzing a query to determine the most efficient way to execute it.
• The database management system (DBMS) uses a query optimizer to determine the most efficient way to execute a query.

A cloud-based e-commerce platform might use query optimization to improve the speed of its product search feature. By optimizing the queries used to retrieve product information from the database, the platform can provide faster and more responsive search results to its users.