I wrote about them here https://blog.logrocket.com/min-max-clamp-css-functions/ - there are some real embarrassments in that article (probably due to me being busy with other things at the time of writing, and being outside my comfort zone [dealing with design]) - example silly statement: "these functions can accept anything that is a number or a calculable value, like the length of a variable, as an input." length of a variable? WTF did I write that for!?!
I could also probably have saved my time because the day after I finished writing it I found this post https://ishadeed.com/article/css-min-max-clamp/ which makes a lot of the same points, less verbosely, and better, with much nicer looking examples because I guess this guy has a design sense.
on edit: I mean I am just jealous of the examples he made, I sweated trying to make something up to show the power of the functions and explain their use and I don't think I did a good job of it, didactically, and his examples were really good. Probably he sweated to, but they look effortless.