a.k.a. users -or- visitors
A term that defines the online audience, it also refers to anyone who "uses" a computer. The term "users" rubs some people the wrong way because, in the past, if you said you were a user, it meant you were habitually consuming an illicit drug. Nowadays, a user is a person who is online. It comes from techies, who refer to people as "computer users."
A user is a particular individual who accesses a Web site. The general nature of the ISP service and individual user actions can make identifying and tracking a user from visit to visit challenging in the Web environment. Whenever possible cookies are employed for this task. When cookies are not available, the user's IP address is used.
How are "cookies" used to identify users? A cookie is essentially a record placed on a user's computer by a Web browser in response to a request from a Web server. The cookie contents are specified by the Web server and can be read only from the domain the cookie specifies from the issuing computer. Cookies typically contain an anonymous and arbitrarily chosen identification number.
What if cookies are not available? When cookie information is not available (either because the Web server does not employ cookies or the user has disabled it), then the user's client Internet protocol (IP) address (along with other information, when available) can be used as an identifier. Note that information based on Internet protocol identification is less reliable than information based on cookies. Internet service providers (ISPs) typically dynamically assign (and reassign) a user an IP address each time they use the service. Thus multiple users of a site may have the same IP address (although at different times).
Historical perspective: As of 2007, the word "users" is not yet in the American Heritage Dictionary, but the word "user-friendly" made it; perhaps that is because we are the first group of people ever to be online users ;-)
NetLingo Classification: Online Jargon