Hot swapping

Hot swapping and hot plugging are terms used to describe the functions of replacing computer system components without shutting down the system. More specifically, hot swapping describes replacing components without significant interruption to the system, while hot plugging describes the addition of components that would expand the system without significant interruption to the operation of the system. Once the appropriate software is installed on the computer, a user can plug and unplug the component without rebooting. A well-known example of this functionality is the Universal Serial Bus (USB) that allows users to add or remove peripheral components such as a mouse, keyboard, or printer.

Computer components are usually described as cold-pluggable if the computer system must be powered down to add or remove them. The opposite term is hot-pluggable; hot-pluggable components can be added or removed without powering down the computer.

In most computer systems, CPUs and memory are coldpluggable, but it is common for high-end servers and mainframes to feature hotplug capability of these components, such as Intel Xeon E7 family or IBM Power 7 and Power 8 processors.