access log

Access log is a file or group of files containing a list of each of the files accessed on a server. Generated when customer has opened a web page. Most servers log the IP address, date, time, file, browser, operating system, or the referring page.

An access log is a list of all the requests for individual files that people have requested from a Web site. These files will include the HTML files and their imbedded graphic images and any other associated files that get transmitted. The access log (sometimes referred to as the "raw data") can be analyzed and summarized by another program.

In general, an access log can be analyzed to tell you:

1. The number of visitors (unique first-time requests) to a home page;
2. The origin of the visitors in terms of their associated server's domain name (for example, visitors from .edu, .com, and .gov sites and from the online services);
3. Number of requests for each page at the site, which can be presented with the pages with most requests listed first;
4. Usage patterns in terms of time of day, day of week, and seasonally;

Below there is one of the lines in the access log:

127.0.0.1 - - [05/Feb/2012:17:11:55 +0000] "GET / HTTP/1.1" 200 140 "-" 
"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.19 (KHTML, like Gecko) 
Chrome/18.0.1025.5 Safari/535.19"