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 interior and exterior doors to provide security and ease of use. The knob allows for easy turning to open or close the door, while the lock can be engaged or disengaged with a key or a thumb turn. These locksets come in various styles and finishes, making them suitable for different types of doors and home decor. Installation is typically straightforward, requiring basic tools. Knob locksets are popular for residential use due to their affordability and accessibility.