title: When does a component unmount?
body: <p>My current understanding is that a component mounts onto the DOM when it is needed to be seen or when the route requires that component. It will also render its child components. Does this mean that a component will be unmounted when you visit a route that doesn't have that component or whenever you visit any page that doesn't show the element that component produces? Thus, a component will need to be remounted every time it shows up on the DOM (outside of prop and state changes), correct?</p>