An access log is a text file that contains an extensive list of all of the files accessed by your Internet site visitors. All of the files which were requested in one way or another will be included, so when you have a PHP script program and a visitor opens just the home page, for instance, you may find plenty of files in the log. The reason is that there are resources on the home page which are embedded - parts of other pages, images, etc. All of these files shall be listed inside the access log, so that you can get a complete picture of the way your website performs. The info is in plain text format, so the logs are often 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, web browser and Operating System. More info, like the referrer website, is oftentimes included too. A log file may be processed by various desktop programs for statistical purposes as an addition to the web statistics created by your server.