I) ls         -> list all the file and directories not including hidden files
II) ls -a     -> list all files including hidden files and directories
III) ls -sort -> list all the files(excluding hidden) in an alphanumeric sorted manner

I) rm *filename*                     -> deletes file/directory
II) rm *multiplefilename with space* -> deletes given files

I) cat *filename*       -> prints the content of file in a single line
II) cat *filename* -n   -> prints the content in its respective lines with $
III) cat *filename* -no ->prints the content in its respective lines with the line number

I) mkdir *filename*                      -> makes a new file/directory
II) mkdir *multiple filename with space* -> makes multiple files/directories with respective name  

Simply outputs the current date

I) echo *text* -> outputs the same texts
II) echo -help -> outputs helptext

I) cd ..           -> takes one directory back
II) cd *directory* -> changes to the given directory

Prints current working directory path