Below is a listing of each of the Linux commands and a brief explanation of what each of the commands do. This is a full listing which means not all the below commands will work with your distribution and may also not work because of your privileges. 

Command              Description
halt                 Stop the computer.
hash                 Remove internal hash table.
hashstat             Display the hash stats.
head                 Displays the first ten lines of a file, unless ot
help                 If computer has online help documentation install
history              Display the history of commands typed.
host                 DNS lookup utility.
hostid               Prints the numeric identifier for the current hos
hostname             Set or print name of current host system.
id                   Shows you the numeric user and group ID on BSD.
ifconfig             Sets up network interfaces. 
ifdown               take a network interface down
ifup                 bring a network interface up
isalist              Display the native instruction sets executable on
jobs                 List the jobs currently running in the background
join                 Joins command forms together.
keylogin             Decrypt the user's secret key.
kill                 Cancels a job.
ksh                  Korn shell command interpreter.
ld                   Link-editor for object files.
ldd                  List dynamic dependencies of executable files or
less                 Opposite of the more command.
lex                  Generate programs for lexical tasks.
link                 Calls the link function to create a link to a fil
ln                   Creates a link to a file.
lo                   Allows you to exit from a program, shell or log y
locate               List files in databases that match a pattern.
login                Signs into a new system.
logname              Returns users login name.
logout               Logs out of a system.
lp                   Prints a file on System V systems.
lpadmin              Configure the LP print service.
lpc                  Line printer control program.
lpq                  Lists the status of all the available printers.
lpr                  Submits print requests.
lprm                 Removes print requests from the print queue.
lpstat               Lists status of the LP print services.
ls                   Lists the contents of a directory.
mach                 Display the processor type of the current host.
mail                 One of the ways that allows you to read/send E-Ma
mailcompat           Provide SunOS 4.x compatibility for the Solaris m
mailx                Mail interactive message processing system.
make                 Executes a list of shell commands associated with
man                  Display a manual of a command.
mesg                 Control if non-root users can send text messages
mii-tool             View, manipulate media-independent interface stat
mkdir                Create a directory.
mkfs                 Build a Linux file system, usually a hard disk pa
more                 Displays text one screen at a time.
mount                Disconnects a file systems and remote resources.
mt                   Magnetic tape control.
mv                   Renames a file or moves it from one directory to
nc                   TCP/IP swiss army knife.
neqn                 Language processors to assist in describing equat
netstat              Shows network status.
newalias             Install new elm aliases for user and/or system.
newform              Change the format of a text file.
newgrp               Log into a new group.
nice                 Invokes a command with an altered scheduling prio
niscat               Display NIS+ tables and objects.
nischmod             Change access rights on a NIS+ object.
nischown             Change the owner of a NIS+ object.
nischttl             Change the time to live value of a NIS+ object.
nisdefaults          Display NIS+ default values.
nisgrep              Utilities for searching NIS+ tables.
nismatch             Utilities for searching NIS+ tables.
nispasswd            Change NIS+ password information.
nistbladm            NIS+ table administration command.
nmap                 Network exploration tool and security / port scan
nohup                Runs a command even if the session is disconnecte
nroff                Formats documents for display or line-printer.
nslookup             Queries a name server for a host or domain lookup
on                   Execute a command on a remote system, but with th
onintr               Shell built-in functions to respond to (hardware)
optisa               Determine which variant instruction set is optima
pack                 Shrinks file into a compressed file.
pagesize             Display the size of a page of memory in bytes, as
passwd               Allows you to change your password.
paste                Merge corresponding or subsequent lines of files.
pax                  Read / write and writes lists of the members of a
pcat                 Compresses file.
perl                 Perl is a programming language optimized for scan
pg                   Files perusal filters for CRTs.
pgrep                Examine the active processes on the system and re
pico                 Simple and very easy to use text editor in the st
pine                 Command line program for Internet News and Email.
ping                 Sends ICMP ECHO_REQUEST packets to network hosts.
pkill                Examine the active processes on the system and re
poweroff             Stop the computer.
pr                   Formats a file to make it look better when printe
priocntl             Display's or set scheduling parameters of specifi
printf               Write formatted output.
ps                   Reports the process status.
pvs                  Display the internal version information of dynam
pwd                  Print the current working directory.
quit                 Allows you to exit from a program, shell or log y

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