UNIQUEUSER
Unique user
According to IFABC Global Web Standards, a unique user is "An IP address plus a further identifier. The term "unique visitor" may be used instead of "unique user" but both terms have essentially the same meaning . Sites may use User Agent, Cookie and/or Registration ID." Note that where users are allocated IP addresses dynamically, this definition may overstate or understate the real number of individual users concerned.The above text is a snippet from Wikipedia: Unique user
and as such is available under the Creative Commons Attribution/Share-Alike License.