$ whatis cat

cat cat (1) - concatenate files and print on the standard output

cat cat (1) - concatenate and display files

Examples:

1. cat -n /etc/networks
2. cat -n /etc/os-release
3. cat /etc/networks
4. cat /etc/networks /etc/os-release
5. cat /etc/os-release
6. cat -n /etc/os-release /etc/networks

Please click on "man cat" to see the Manual Page for this command.