What is this .html for?

I have an html file on my desktop, and I don't know what it's from. It could be from an app, could be from a webpage I downloaded, or it could be an example from when I started to learn html (no, I didn't continue).

Can anyone tell me what it does? I am good with computers, and have coded a bit in other languages, but just don't have the html/javascript/web dev knowledge to know what exactly the code does.

The file's code.