Not sure what you're getting at. Users in Google Analytics are tied to a browser cookie. So If I come to your site from the same machine on 3 different browsers, that's 3 cookies and 3 users.
The data is aggregated in reports from ALL (regardless of from where it came) hits sent to GA with your Account and Property Id. When received, the IP address and other info is used to determine location and is stored as a dimension of the user. In the Audience >> GEO section you can drill into location.
Hope that helps!