The <aside> thing

Question

i didn't understend the <aside> thing correctly

Answer 1

Tags like <aside>, <nav>, <article>, etc. are just used to make the markup clearer and easier to manage.
So for example, if you were to make a side bar, you could make it in an <aside> tag so when you look over the code or maybe you want to style it in css, its a bit easier to tell what it is.

In reality you could use <div> for everything, as it functions the same as, for example, an <aside>

Answer 2

https://www.w3schools.com/tags/tag_aside.asp
http://www.html5-tutorials.org/new-section-tags/aside-tag/