When an HTML file is accessed, it is logged in the World Wide Web server log file as a sequence of hits - one for the HTML file itself and one for each embedded element within the HTML file. A qualified hit is any requested file that successfully arrives and is displayed at the patron's workstation. This eliminates the counting of files which were requested by the patron but were never completely delivered due to server error or patron cancellation, redirects, and requests by computer programs such as web crawlers which index information on the Internet. Qualified hits are therefore a subset of all hits. A page hit is a requested HTML file that successfully arrives and is displayed at a user's workstation.
Page hits are therefore a subset of qualified hits.
When counting page hits only the originally requested HTML file, or page, is counted and any additional elements embedded within the HTML file are not counted. A visit represents consecutive file requests made at a World Wide Web site by one user, determined by their Internet address. A user's visit continues for as long as they keep accessing files on the World Wide Web server. If more than 30 minutes elapses between a user's file requests, a new visit is considered to have begun for that user. This has been facilitated by the use of the Unix operating system on each of these platforms.