Syslog
From Hackepedia
Syslog is the common way of managing logfiles on UNIX. Processes that wish to log something write to a UNIX socket usually bound in /dev/log which then goes to syslogd that writes these logs to a file usually found in /var/log. Syslog has different facilities which are a series of different log categories and priorities which is self explanatory. High syslog priorities notify the entire system so that these logs do not get missed.