Google Analytics _ga Cookie

Hi Guys,

I’m a real novice, but learning everyday, on this website i’ve created for a customer, but not put live yet against the correct domain, it shows in the cookies a _ga cookie, is this directly related to google analytics, if so why would it be there as i have never used google analytics on this domain ever?

Thanks in advance for any help… ??

The page I need help with: [log in to see the link]