Hot Plugging describes the ability to connect, or disconnect hardware while the host computer or device is active.
If you look at manuals/user guides for older devices, they normally require you to switch off a machine before adding or removing them. It is obviously a great convenience not to need to do this.
One of the key advantages of the Universal Serial Bus is this ability.
Time to build your own robot! Using a Raspberry Pi with parts and some time, you can use my book to learn how to make and program a robot with automatic behaviours.