A log file is a text file that is divided into two general
areas: the header and the log entries. The header, which appears
first in the log file, contains data about the log file. The log
entries contain data about client
activity. This section contains tables that provide reference
information about the fields that appear in the log file header and
log file entries. This section also contains a table of the
wildcard characters you can add to a log file name if you want a
log file name to be more meaningful.