Every time any page is requested from your website by a human or another program or an automated bot, the event is tracked in a log file that is stored on the web server. If you have installed Google Analytics, then google will tell you all about the visitor and page analytics. It will tell you how many users, what are the top pages etc. In the case of Log File Analyzer, you can get similar insights into your visitor statistics and page analytics.
So what is the difference between Google Analytics and Log File Analysis?
What do you do with the information that a typical Log File Analyser generates?
The main difference is Google Analytics will track only the pages that have the GA code added to them. It will miss any information on other pages that does not have the GA code simply because it just cannot see them and won't be able to report on them.
What is Technical SEO and how does it relate to Log File Analysis?