Server Log Files
Server log files are files located on a server that store data associated with requests for web pages. The server log is created and updated by a web server (for example Apache or Microsoft Internet Information Services). Examples of data stored in the log files include time of request, visitor's ip address, page requested, visitor's browser & operating system, errors, referees, etc. Before the age of online analytics services such as Google Analytics and Adobe Analytics, website owners would use programs that aggregated the log file data to create web traffic reports. Today, log files can be used as a forensic tool to help investigate hacking attacks against a website.