The two main methods for tracking websites and monitoring site usage statistics are ‘JavaScript Page Tagging’ and ‘Log File Analysis’.
Google Analytics is a great example of how JavaScript technology can be utilised to track websites. Other packages such as AWStats and LiveStats are prime examples of Log File tracking. The fact that each application uses different technology to collect data, explains why the reported numbers tend to vary between them. It’s essentially the same data viewed in an alternative way.
Advanced Web Statistics (AWStats) is a cross-platform, open source log file analyser, capable of interpreting a variety of different log file formats. The official documentation for AWStats is generally targeted towards system administrators rather than your average website owner. To sum it up, it’s not much help in figuring out what the statistics are showing you. Google Analytics and AWStats offer differing features and each have their own strengths and weaknesses. For most things however, Google Analytics essentially runs circles around AWStats. On the flip-side, for some things Google Analytics uses an alternative methodology, which sometimes can have its own drawbacks.