What is an iframe and how can I use it?

The so called inline frame or iframe is a powerful HTML-tag which allows you to display a second, separate webpage within your main webpage. The <iframe>tag is used to define such inline frames in your pages. The video below was copied from the SWITCHtube webpage by adding the following embed code on this help page.

iframe code = <iframe src="https://tube.switch.ch/embed/e88f2b99" width="100%" height="650" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>