Uptime command is very simple and useful in Linux , Give information about system current time, how long the system has been running, the number of users logged on and server load average.

# uptime

 09:51:19 up  9:14,  2 users,  load average: 1.04, 0.64, 0.56

The current server time is :  09:51:19, System uptime :  9 Hours 14 Minutes over, 2 User logged on server  and  the system load averages for the past 1, 5, and 15 minutes 1.04, 0.64, 0.56.

Likewise, we can discover the same information available on W command,
 
# uptime -V

procps version 3.2.7

 /var/run/utmp :  information about who is currently logged on
 /proc  :     process information