An access log is a text file containing a thorough list of all the files accessed by your site visitors. All of the files that were requested in one way or another shall be included, so if you have a PHP script program and a site visitor opens just the home page, for example, you may find many files in the log. This is because there are resources on the home page which are embedded - parts of other web pages, pictures, and so on. These files shall be listed in the access log, so that you can get a detailed picture of the way your website works. The info is in plain text format, so the logs are frequently referred to as "raw data" too. An access log provides the name of each requested file, the path to it, the date it was accessed, and also the user’s IP address, browser and Operating System. More information, like the referrer Internet site, is usually provided too. A log file could be processed by various desktop apps for statistical purposes as an addition to the web statistics generated by your web server.