Why iframe is not working with some websites?

Question

I set iframe to
http://www.google.com
Its not working explain it please. 🤕

Answer 1

There's a way for a website to allow/disallow embedding itself in an iframe by setting HTTP header x-frame-options.

In your case, google sets x-frame-options: SAMEORIGIN - which means that googles disallow loading of the resource in an iframe outside of their domain.