Web Components, Vue and React

Hello,

I've been reading a lot about Polymer and all it's web components shenanigans but I'm always left with doubt.

I understand that WebComponents are meant to use the DOM as the framework so they are native and that's good, but what's the difference between that and React/Vue? We are also creating custom html tags...

So, correct me if I'm wrong, but the main difference is that the custom tags we create using Vue/React are only rendered through those libs whilst WebComponents will be rendered through the browser, not needing any other installation?

I am so confused.