Linux/MacOS			      Windows
----------------------------------------------------------------------------
current directory listing			  ls					          dir
list all files formatted			  ls -a				          dir /A
list all sub-directories			  ls -R				          tree
list your current location		  pwd					          chdir
change directory					      cd					          cd
make a new directory				    mkdir				          mkdir
remove a directory					    rmdir				          rmdir
remove a directory recursively	rm -r				          rmdir /S
remove a file						        rm				            del
copy a file							        cp				            copy
copy a file or directory rec.		cp -r			            xcopy
dump file content to screen			cat				            type
pipe a single page at a time		more				          more
clear the screen					      clear				          cls
leave the shell						      exit				          exit
dump system variable to screen	echo $VARIABLE	      VARIABLE
                                                      
build in editors				      	vim, pico, emacs    	edit
show current computer usage			top					          tasklist

quick help for commands				  COMMAND --help		    help COMMAND
detailed help						        man COMMAND			      COMMAND /?

there is many more to find on the web ...

.! ls