What are the common log files?

…Apache provides a complete logging system which can be incredibly useful for…a number of purposes.…Three of the most common include, finding problems with a site, such as a server or…authentication errors, analyzing traffic patterns including who accessed what.…This is becoming less common with third party tools like Google Analytics, but…it's still important.…Finally, log files can be used for…detecting malicious activity, like brute force attacks or vulnerability scans.…Apache includes several different logging mechanisms.…

Each of which is described in detail at Apache.org.…If you're looking to make changes, I'd recommend bookmarking this page.…In general, log files can be a single monolithic file, a file that is rotated or…started fresh on a regular basis with archives made.…Or even piped directly to another program.…The format of the log file can be configured.…There is logical defaults that can be safely relied on with no changes.…But these can be overridden.…The most important log file is the error log which stores diagnostic information…