A logfile is a file, in which the processes that take place in a computer or network system are logged. Logfiles provide important data for the analysis of networks or access to a webserver or a website. Logfile analysis used to be the most common way to get data on visitors to a website.
A logfile will generally always contain the same information. Usually only the sequence of the information varies. The most common formats for logfiles are NCSA, W3SVC, Microsoft IIS3.0, and O'Reilly.
Each logfile contains individual lines called hits. The data, which is transmitted from a server to a client, is logged in these hits with a time stamp. The following information is contained in a logfile:
Logfiles provide SEO with important clues about visitor origin and behavior. Important data for optimizing websites can be gained from this information. Moreover, logfiles can be used as control files, to check the correct operation of analytical tools such as Google Analytics. Server errors or crashes can be better traced using logfiles. Especially since the accessibility of a website and its subpages is relevant for the assessment of the website by search engine robots, logfiles have an important role in error analysis. At the same time, the usability of a website can also be interpreted with a logfile analysis.