uname -a 	 #used to print the system information
uname -r	#Print the kernel release 
uptime	#Display the time since the last boot
hostname	#Get host name 
hostname -i	#Host name ip address
last reboot	#Last reboot time
date	#Date information
cal	#Carlander information 
w	#provides a quick summary of every user logged into a computer,
whoami      #Display username of the current user 
who	#display the users that are currently logged into your Unix computer system
id 	#Print user id and group id information
df -h	#Disk space information
df -t	#Disk types