If you installed this Firefox version in your Home directory (i.e. a location with write permission) then Firefox can update without a problem if you have set in Options/Preferences to update automatically. If you do not update automatically or you installed Firefox in a location owned by root like /usr/local or /opt then you are notified when an update is available and will see a green dot attached to the "3-bar" Firefox menu button. If you install Firefox from your distro's repositories then updates are handled by this distro.