An access log is a text file that contains a thorough list of all 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 program and a website visitor opens only the home page, for example, you may find a lot of files inside the log. It is because there are resources on the home page which are embedded - parts of other webpages, pictures, etcetera. All these files will be listed in the access log, so you're able to get a detailed picture of the way your website performs. The information is in plain text format, so the logs are occasionally referred to as "raw data" too. 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, world-wide web browser and OS. Additional information, such as the referrer Internet site, is oftentimes included too. A log file could be processed by various desktop apps for statistical purposes as an addition to the web stats provided by your hosting server.