What does the SQL command 'UPDATE' accomplish?

The SQL command 'UPDATE' is designed to modify existing records within a table. When executed, it allows for the alteration of one or more columns in rows that meet specified criteria. This command is essential for adjusting data as business requirements evolve or correcting inaccuracies within a database.

For instance, if a company's employee database needs to reflect a recent promotion by changing an employee's salary, the 'UPDATE' command would be the appropriate tool to accomplish this. The command typically includes the 'SET' keyword to define which column values should be changed, alongside a 'WHERE' clause to determine which rows should be updated.

The other choices are associated with different SQL commands: deleting records is handled by the 'DELETE' command, creating new entries is done through the 'INSERT' command, and retrieving data is accomplished with the 'SELECT' command. Each of these functions serves a distinct purpose in SQL, highlighting how 'UPDATE' specifically focuses on changing existing data.