A knob lock is a type of locking mechanism commonly found on doors. It consists of a round knob that can be turned to open or close the door. When the knob is turned, it engages or disengages a latch, allowing the door to be secured or opened. Knob locks are often used for interior doors, such as bedrooms and bathrooms, as well as for some exterior doors. These locks typically come with a keyhole on one side, allowing for key access from the outside. They are generally easy to install and operate, making them a popular choice for residential use. However, knob locks may not provide the same level of security as more advanced locking systems, such as deadbolts.