HTML5: Article, section or div?

Question

How can I know when I've to use those options to divide my webpage?

Answer 1

Article = blog/ news story
Section = a section of the document that makes sense if that were the only thing on the page
div = everything else

You should also be using HTML5 semantic markup such as <header><main><aside> and <footer>

Answer 2

Article = blog/news/info articles
Section = a section inside article
div = anything

but it is only to make your code easier to read. so, you can use <article> inside <footer> nor <header> because it is like a custom tag

an Info:
you can even make your own tag like this <gggg>, <anything>, or <lol> in your html files, because html is xml based.

Answer 3

These tags are called semantic tags it does not make any visual diffrence, but it makes your code more readable and logical.