Variations Question

I am new to SharePoint 2013 Variations.

I created a root-site with EN-US and label with FR-FR.  The contents are recreated successfully and the URLs are following:

http://site

http://site/en-us

http://site/fr-fr

I wanted to know:

- Should I give separate URLs for each country users (US & France)?

Or

- Giving the base URL http://site, based on the Browser settings will there be redirects to correct language-site?

Please let me know.