This thing there,

That header is present on every page, so it's loaded once and never again.

Website shell

Load your website's main stylesheet, JavaScript, markdown, and other assets once and keep them around between page navigations. Saving bandwidth and increases page load times considerably.

Navigate any element

Sometimes you just want to update a portion of your website. That can be done programmatically with JavaScript or directly in the markdown using the vv attributes.

..or include that page with the response

Vevisir pages, snippets, and other PHP files can be inlined with the response using VV::include.