Difference between section and div tag ?

Answer 1

In HTML, <section> means that the content inside is grouped and should appear as a entry in an outline of a page whereas <div> does not convey any meaning, aside from any found in its class, lang and title attributes.

Answer 2

well, using section tag is more friendly for search engine robots. semantic correct way is to use section obviously in different sections:
like, menu, side_bar_l, side_bar_r, comments, main etc

Answer 3

You can check this post:
https://www.sololearn.com/discuss/2079366/?ref=app
https://www.sololearn.com/discuss/2828881/?ref=app