Linux log files location and how do I view logs files?

Linux log files location and how do I view logs files?

Go to /var/logs directory:
# cd /var/logs
View common log file /var/log/messages using any one of the following command:
# tail -f /var/log/messages
# less /var/log/messages
# more -f /var/log/messages
# vi /var/log/messages
Output:

Jul 17 22:04:25 router  dnsprobe[276]: dns query failed
Jul 17 22:04:29 router last message repeated 2 times
Jul 17 22:04:29 router  dnsprobe[276]: Primary DNS server Is Down... Switching To Secondary DNS server
Jul 17 22:05:08 router  dnsprobe[276]: Switching Back To Primary DNS server
Jul 17 22:26:11 debian -- MARK --
Jul 17 22:46:11 debian -- MARK --
Jul 17 22:47:36 router  -- MARK --
Jul 17 22:47:36 router  dnsprobe[276]: dns query failed
Jul 17 22:47:38  debian kernel: rtc: lost some interrupts at 1024Hz.
Jun 17 22:47:39  debian kernel: IN=eth0 OUT= MAC=00:0f:ea:91:04:07:00:0