Definition - What does External Interrupt mean?
Techopedia explains External Interrupt
There are many different kinds of external interrupts. IT professionals characterize user requests for process changes as external interrupts. If a hardware device asks the operating system to change processes, this could also be called an external interrupt.
External interrupts can also come from errors or other events that change the way that the computer works on any given set of instructions. Many types of external interrupts have their own labels and handling protocols. Engineers, developers and other IT professionals work to understand specific types of external interrupts in order to know how to handle them.
An input/output device may request some type of operation from the computer’s processor, in which case the system may be interrupted from what it was previously doing. This would be an example of an external interrupt. These types of external interrupts can be quite different from situations where users are clicking on buttons and controls and causing the computer to prioritize multiple programs in different ways. Generally, engineers try to make an operating system respond to user requests in real-time, so that there is no inconvenience, and so that the system appears to be handling all sorts of simultaneous tasks.