An access log is a text file that contains a thorough report on all the files accessed by your site visitors. All of the files that were requested in one way or another will be included, so if you have a PHP script program and a visitor opens just the home page, for instance, you may find a lot of files inside the log. It is because there are elements on the home page which are embedded - parts of other webpages, images, and so forth. These files shall be listed inside the access log, so you can get a detailed picture of the way your site functions. The information is in plain text format, so the logs are often called "raw data" too. An access log shows the name of each requested file, the path to it, the date it was accessed, along with the user’s IP address, browser and OS. More information, including the referrer site, is sometimes provided as well. A log file can be processed by various desktop apps for statistical purposes as an addition to the web stats provided by your website hosting server.