An access log is a text file containing a full list of all of 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 application and a website visitor opens just the home page, for instance, you may find many files in the log. It is because there are things on the home page that are embedded - parts of other pages, graphics, and so forth. All of these files shall be listed in the access log, so that you can get a detailed picture of the way your website performs. The information is in plain text format, so the logs are often referred to as "raw data" as well. An access log provides 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 sometimes included too. A log file could be processed by various desktop apps for statistical purposes as an addition to the web statistics generated by your server.