What is the Kensington Security Slot on the laptop? What does it do?

Notebook Lock from Loxit Flexible Laptop Security Master Keyed Simple Operation With Keying Options

You can secure you Dell desktop, laptop, docking stations or monitors with a cable, using the security slot

security lock slot lock It effortlessly latches directly into a laptop or other device equipped with the industry standard Kensington® K-Slot security-lock slot, providing

security cable slot slot in double aluminum-framed doors) • Stop: A protrusion that stops a door and keeps it from swinging past the jamb • Lock: Various types of locking