An access log includes a record of all the files which have been requested by the visitors while browsing your Internet site. The list is thorough, so when you have a web page with 2 embedded images, for instance, all of the three files shall be in the log, not only the page. An access log typically contains the date, the OS, the Internet browser and the IP address for every file in human-readable form, so you can get a good idea about the most well liked files on your website. The log, that's also commonly named "raw data", is an addition to the web data which you usually get with a hosting account, not a replacement. An example why you may need such a log is if you want to use some software on your computer system to prepare a report about the website’s general performance, but you don't want to use the conventional graphs and tables that come with the server-generated web statistics.