DROP is a SQL command that can be used to remove a database permanently from a database management system. DENY is a SQL command that can be used to revoke permissions from a user or role. ALTER is a SQL command that can be used to modify the structure of a database object, such as a table or column. DUMP is not a valid SQL command, but it may refer to a backup operation that creates a copy of a database. References: The Official CompTIA IT Fundamentals (ITF+) Student Guide (Exam FC0-U61), Chapter 6: Database Fundamentals1