Please can someone explain frames to me. Some people might say it is not important but i want to understand it.

Question

I don't understand <frameset>,<frame>,<frameset cols="...",<iframes>.

Answer 1

No, you doesn't need that: frameset are outdated and deprecated since HTML5.

There's no reason to use them today, and if you want to embed other web content in your page you could always do similar things in HTML5 much simpler and more flexible with <iframe> element(s) (with the benefit of avoiding ugly Html4.x doctypes (specific to each variants, where frameset are such variant) ;)

Answer 2

Where can I learn about iframes?

Answer 3

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe