ActivatedRoute

The ActivatedRoute  interface provides access to the url, params, data, queryParams, and fragment observables. We will look at each of them in detail, but first let's examine the relationships between them.

URL changes are the source of any changes in a route. And it has to be this way as the user has the ability to modify the location directly.

Any time the URL changes, the router derives a new set of parameters from it: the router takes the positional parameters (for example, :id) of the matched URL segments and the matrix parameters of the last matched URL segment and combines those. This operation is pure: the URL has to change for the parameters to change. Or in other words, the same URL will always result in the same set of parameters.

Next, the router invokes the route's data resolvers and combines the result with the provided static data. Since data resolvers are arbitrary functions, the router cannot guarantee that you will get the same object when given the same URL...