POST tells the server that data is following. HEAD is used by link checking programs, not browsers, and downloads just the information in the HEAD tag information. The specific level of HTTP protocol is also recorded. A status code of 200 means the transaction was successful. This occurs when the server checks if the version of the file or graphic already in cache is still the current version and directs the browser to use the cached version.
Sever errors are red flags for the server administrator.
For GET HTTP transactions, the last field is the number of bytes transferred. The transfer volume statistic marks the end of the common log file. Lets look at these fields. The referrer URL indicates the page where the visitor was located when making the next request. If you were looking at just the referer log, not integrated into the transfer log, it would be made up of just two fields.