A failed request can be caused by a number of things, including typos on the user's end. However, if this number gets extremely large, it probably means that you have a broken hypertext link in one of your web pages. If a thorough search through your web site doesn't turn up any broken links, then you may want to examine the Referrer Report , because a remote web site may be pointing to a non-existent file in your web space. The number of distinct files means exactly what it sounds like. In this example, twenty-six different files have been requested from the web site during the past week.
Distinct hosts are another important number.
Each unique host that has accessed a web page or file on your site adds to this number. However, it is important to keep in mind that given the fact that most people are accessing the World Wide Web via small ISPs these days, sometimes repeat customers will show up as a different distinct host every time they access your page. This is a number which should be more useful. Corrupt logfile lines are entries in the web access log that are used by the system for various other functions. Unwanted logfile entries are all the rest of the entries in the access log.