Originally a program used by a system administrator which displayed the identities of all the users who were logged in to a network. It was based on the Finger program used in UNIX. However, the term has been extended to describe any utility which looks up user details such as their name, given an email address. The information provided by a Finger utility is usually taken from the member details held by an Internet service provider. There are a large number of Web-based interfaces to Finger systems.