This is known as an "iframe". This allows you to embed content from another source into a HTML document (Such as a website like above)
However, Major Websites have disabled people being able to embed their website as this is often abused by Hackers steal information such as Login Information,etc
However you can use this website (which suprisingly still allows embeding) as if you actually googled this and went on their Website.
(by they way, this is a website that teaches you CSS Flexbox and its great, Ive tried it myself so I can Vouch for it)
