Check out example codes for "how to use iframe in html". It will help you in understanding the concepts better.

Code Example 1

<iframe src="http://kidcreatorsteam.com" height="90px" width="40px"></iframe>
<!--I made an iframe! Yay! -->

Code Example 2

<iframe width="560" height="315" src="https://www.youtube.com/embed/owsfdh4gxyc" frameborder="0" allowfullscreen></iframe>

Code Example 3

<iframe src="demo_iframe.htm" height="200" width="300"></iframe>

Code Example 4

<iframe src="https://www.w3schools.com" title="W3Schools Free 
    Online Web Tutorials"></iframe>

Learn ReactJs, React Native from akashmittal.com