How to understand IDL in html spec?

Question

HTML

Began to get acquainted with the specification and the question arose:
1. What is IDL, and how to understand it? https://html.spec.whatwg.org/multipage/introductio...
2. And what is the difference between Multipage Version and Developer Version. https://html.spec.whatwg.org/multipage/ , https://html.spec.whatwg.org/dev/
It will even be more accurate if you ask a question like: " which one is better to read, and why? "

Answer 1

yes, anyone, even this one - https://www.w3.org/TR/2014/REC-html5-20141028/
are you going to look for differences with a magnifying glass in every nightly assembly?
if you get carried away like that, you need to start with html2, everything is warm and lamp-like there
https://www.w3.org/MarkUp/html-spec/html-spec_toc.html
and about idl, well, it’s googled - https://ru.stackoverflow .com/questions/527205/What-...