A “user” is an individual who visits your website on one or more occasions. Ideally, the user is related to a quick-converting customer, from any source.
The retailer in this case takes advantage of cookies, which store, track and provide many user behaviors. There is also a collection of user attributes related to the browsers and IP address is shown.
Although not mandatory, this is highly accurate. It’s also important for the retailer to differentiate between total users (based on number of visits to your site) and “unique” users (how many different users visited your site, despite a number of times visited