What Do You Know? Dhimmi, Jewish Legal Status under Muslim Rule

In the series What Do You Know?, we feature scholars’ answers to questions about Jewish history and culture submitted by our readers.

An anonymous reader writes: I would be interested in getting a better understanding of the ebb and flow of dhimmi status over the centuries, and how that affects the way they are treated today.

What does dhimmi mean, where did it come from, and is it still relevant?