How to get command Information

How to get command Information in Linux ? 

Q: How to find out where the binary of a command I'm running?
A: You can use type command (available on both zsh and bash):


[root@amitmaheshwari.in]# type ls 
ls is an alias for ls -h --color=auto

[root@amitmaheshwari.in]# type cat 
cat is /bin/cat

[root@amitmaheshwari.in]# type alias 
alias is a shell builtin

Q : How to check command help ?
A: Following ways to check command help
# commandname --help
#
whatis commandname
#
man commandname

$ ls --help
$ whatis ls
$ man ls