Often it may be difficult to explain how bitcoin works to the average layperson. There have been many attempts at simplifications, some great, some less so.
The video at the bottom of this page is the best I have seen so far… in terms of simplicity, speed (2:22), and accessibility to folks that e.g don't know reddit exists, let alone bitcoin. It's not perfectly accurate sure, but that's not the goal.
(Apologies I am not sure how to link directly to a BBC video – you need to scroll down to the video at the bottom)