The history of web site measurement is, for the most part, the history of web server logfiles. Understanding the data logfiles provide and their limitations will help you better plan for their use.
Web measurement got its start over 10 years ago with simple log analysis tools. These early tools did little more than scan the logfiles produced by web servers to count hits and visits, report on server errors and page load times, and process other data pertinent to early site administrators.
Using the following sample line from the author's web server logfile, let's step through the fields captured in the combined log format (see below for more formats).
18.104.22.168 - elvis [15/May/2000:23:03:36 -0800] "GET /index.htm HTTP/1. 0" 200 956 "http://www.webanalyticsdemystified.com/index.asp" "Mozilla/2.0 (compatible; ...