This gets shared a ton, but the old Bell Labs video from 4:56 to 10:52 is still the best way I have seen pipes explained:
Nit: You can get a link to a specific time in the video by clicking the "share" button and ticking "start at": https://youtu.be/tc4ROCJYbm0?&t=296
It's amazing how these ideas conceived almost 50 years ago still are helpful for new computer users today. Just goes to show how well planned it was.
Great video, when I first watched it, it switched my thinking from "why is *nix so hard to use" to understanding they were really trying to build with the user in mind and to learn more about the "*nix way" to work with it, not against it.