A knob lockset is a type of door hardware that combines a doorknob and a locking mechanism in one unit. It is commonly used on residential doors, providing both functionality and security. The knob allows users to easily open and close the door, while the lock ensures that the door can be secured when needed. Typically, knob locksets are available in various styles and finishes to match different door designs. They can be installed on interior or exterior doors, although they are often recommended for interior use due to their vulnerability to forced entry compared to other lock types, such as deadbolts.