What happens when a user lands directly on 2nd or 3rd level page and have not "jumped" from 1st level page?
Let's take an example. Say we have a website with 3 pages:
- Homepage "website.com/"
- Products "website.com/products"
- About "website.com/about"
Your browser can load any of these pages directly, as usual. But when you are on the homepage (for example) and you click on the "About" link, µJS load the "/about" URL, and replace the current page's `<body>` tag with the fetched page's one.
It's that simple.