One Thing a still struggle to understand is how a single page app routing works: if I navigate to the app url (let's say app.com), the app get loaded from the server to the browser, and I'm ok with it. if I explicitly write the url of a subpath (e.g. app.com/contacts), this url get catched by the app that redirects me to its inner route, when I expect that browser should send the request to the server. So, what I don't understand is how the browser "knows" the a specific subpath should be managed but the single page app.

How React router works avoid GET to reach web-server

One Thing a still struggle to understand is how a single page app routing works:

if I navigate to the app url (let's say app.com), the app get loaded from the server to the browser, and I'm ok with it.
if I explicitly write the url of a subpath (e.g. app.com/contacts), this url get catched by the app that redirects me to its inner route, when I expect that browser should send the request to the server.

So, what I don't understand is how the browser "knows" the a specific subpath should be managed but the single page app.