An access log is a text file containing an extensive list of all the files accessed by your website visitors. All the files that were requested in one way or another will be included, so when you have a PHP script app and a visitor opens just the home page, for instance, you might find plenty of files in the log. The reason is that there are components on the home page which are embedded - parts of other web pages, images, etc. All these files will be listed within the access log, so that you can get a full picture of the way your site works. The information is in plain text format, so the logs are often referred to as "raw data" as well. An access log contains the name of every requested file, the path to it, the date it was accessed, as well as the user’s IP address, Internet browser and OS. Additional information, like the referrer Internet site, is usually supplied as well. A log file can be processed by various desktop applications for statistical purposes as an addition to the web stats supplied by your hosting server.