Microsoft visited my campus, and I was invited to a campus interview after submitting my resume a few weeks ago.

I met one-on-one with the interviewer, who was an Indian hardware verification engineer at Microsoft. The questions were mostly related to the Operating System.

He asked me to describe how a scheduler works in the real world and, at a low level, how interrupts function. I suspect my description of interrupts was not entirely accurate, and I was unprepared for this type of question.

He also inquired about the most impressive project I had completed and why.

Assume I know nothing about interrupts. Please explain to me what an interrupt is and how it works.