A unique user is a term in web analytics that refers to data of a Pageview of a unique IP, whose presence is only counted once, regardless of the number of pages they visit.
[1] A website's number of unique users is measured over a standard period of time.
[3] It can also be used to demonstrate website popularity and performance to potential advertisers and investors.
[5] Measuring unique user data can be distorted by automatic activity, for example, bots or other instances of the website being opened where there is no human present or interacting with the website.
Estimations of unique user traffic statistics are usually filtered to remove this type of activity by eliminating known IP addresses for bots, by requiring registration or cookies, or by using panel data.