Which SQL command is used to modify existing records in a database?

The SQL command used to modify existing records in a database is UPDATE. This command allows you to change the values of one or more columns in a table for the rows that meet certain criteria. By specifying the table to update, the columns to modify, and the conditions for which rows to affect, the UPDATE command provides a flexible way to manage and manipulate data stored within a database.

For example, if you want to change the email address of a specific user in a user table, you would use the UPDATE command followed by the SET clause to define the new value and a WHERE clause to specify which user's record should be modified.

The other options serve different purposes: INSERT INTO is used for adding new records to a table, CREATE TABLE creates a new table in a database, and ORDER BY is employed to sort the result set of a SELECT statement based on one or more columns. Each of these commands plays an important role in database management but does not modify existing data like the UPDATE command does.