Returning Visits - Based purely on a cookie, if this person is returning to your website for another visit an hour or more later

First Time Visits - Based purely on a cookie, if this person has no cookie then this is considered their first time at your website.

Unique Visitor - Based purely on a cookie, this is the total of the returning visits and first time visits - all your visitors.

Page Load - The number of times your page has been visited.