An access log is a text file containing an extensive report on all of the files accessed by your website visitors. All the files which were requested in one way or another shall be included, so when you have a PHP script program and a website visitor opens just the home page, for example, you might find numerous files in the log. This is because there are elements on the home page that are embedded - parts of other pages, graphics, etcetera. All of these files will be listed within the access log, so that you can get a complete picture of the way your site performs. The info is in plain text format, so the logs are sometimes referred to as "raw data" as well. An access log contains the name of each requested file, the path to it, the date it was accessed, plus the user’s IP address, browser and OS. More information, like the referrer website, is oftentimes provided as well. A log file could be processed by various desktop applications for statistical purposes as an addition to the web statistics supplied by your hosting server.