Command:   cat - concatenate files and write them to stdout
Syntax:    cat [-u] [file] ...
Flags:     -u  Unbuffered output
Examples:  cat file                 # Display file on the terminal
           cat file1 file2 | lpr    #  Concatenate  2  files  and  print
                                      result

     Cat concatenates its input files and copies the result  to  stdout.
If  no input file is named, or - is encountered as a file name, standard
input is used.  Output is buffered in 512 byte blocks unless the -u flag
is  given.   If you just want to copy a file, cp should be used since it
is faster.