An error log is a list of the error messages and warnings that appeared for one reason or another while your visitors were surfing around your Internet site. Such a log features raw information on the way the web server has dealt with requests a number of situations. An error message could appear if, for instance, a link leads to a page or a file that is not on the hosting server, if the code on a particular page can't be processed, if any individual is trying to access the website or its back office using an IP address that's blocked by an .htaccess rule and many others. The info in the error log offers the IP of the website visitor, what error message came out and the reason for the web server to display it, the full path to the file which induced the error and the specific time of the event. Having this data will enable you to learn if any part of your Internet site has a problem, which you can then fix. Therefore, your website visitors will have a better experience and you may optimize the site for best performance.