Are sessions destroyed when I close the browser tab?

As far as I know sessions are destroyed when you close a browser window, with my application when I test it on Chrome the cookie storing the session id somehow remains stored on the pc (even though Chrome is set to delete cookies on browser close), but when I access my application again after closing chrome the login screen is displayed, meaning that the session has been destroyed and I need to login again.

On Firefox however, when I close it and reopen and try to access a secure page I still get allowed in, why could this be happening?

Closing tabs does not end sessions only until the browser is closed will it destroy the session. Assuming you didn’t tell the browser to always save sessions on close.