What does the ‘cat’ command do in UNIX system?

The cat command is use to display the content of a file
Syntax--
     cat [options] [file]
Common Options
     -n    precede each line with a line number
     -v    display non-printing characters, except tabs, new-lines, and form-feeds
     -e    display $ at the end of each line
Examples
     % cat filename
You can list a series of files on the command line, and cat will concatenate them, starting each in turn, immediately after completing the previous one, e.g.:
     % cat file1 file2 file3