Answer Description

A cable lock will physically secure the laptop to a desk, counter, or table. This will keep the laptops from being stolen, but still portable when unlocked.

Wikipedia

A Kensington Security Slot (also called a K-Slot or Kensington lock) is part of an anti-theft system designed in the mid 1980s and patented by Kryptonite in 1999–2000, assigned to Schlage in 2002, and since 2005 owned and marketed by Kensington Computer Products Group, a division of ACCO Brands.