Which CRUD operation modifies an existing table or view?

The correct answer is update. In the context of CRUD operations (Create, Read, Update, Delete), "update" is specifically designed to modify existing data within a table or view. Let's look at why the other options are incorrect: Read: This operation retrieves data from a table or view without making any changes to it. Replace: While some database systems might have a "replace" command, it typically functions as a combination of delete and insert, or an update if the record exists, rather than a standalone CRUD operation for modification. The standard CRUD term for modifying existing data is "update." Create: This operation is used to add new data (rows) to a table. It does not modify existing data.