cat - concatenate and print files
cat [-u] [-s] [ file1 [ file2 ... ]]
reads each file in sequence and writes it on the standard output.
If the command line contains no input file, or if it contains the
reads from the standard input. Input files can refer
devices as well as satellite files.
Do not use buffering. Normal behaviour is to buffer output in
operate silently i.e. do not complain about non-existent files.
prints the file on the standard output.
cat file1 file2 > file3
concatenates the first two files and places the result on the third.