An access log is a text file containing a full list of all of the files accessed by your site visitors. All the files that 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 inside the log. This is because there are things on the home page which are embedded - parts of other pages, graphics, and so forth. All of these files shall be listed in the access log, so you can get a detailed picture of the way your site performs. The info is in plain text format, so the logs are often called "raw data" as well. An access log contains the name of each and every requested file, the path to it, the date it was accessed, in addition to the user’s IP address, Internet browser and Operating System. More information, such as the referrer website, is typically provided as well. A log file can be processed by various desktop applications for statistical purposes as an addition to the web stats generated by your web server.