When building web applications, we will likely need to mutate the address the user sees within the browser to reflect the current resource being accessed. This is a core tenet of how browsers and HTTP work. An HTTP address should represent a resource. And so, when the user wishes to change the resource they are viewing, the address should correspondingly change.
Historically, the only way of mutating the current URL within the browser would be for the user to navigate to a different page via an <a href> or similar. When SPAs started to become popular, however, JavaScript programmers needed to get creative. In the early days, a popular hack would be to mutate the hash component of a URL (example.org/path/#hash), which would ...
