Link: How to Install and Configure UFW – An Un-complicated FireWall in Debian/Ubuntu

The ufw (Uncomplicated Firewall) is an frontend for most widely used iptables firewall and it is well comfortable for host-based firewalls. ufw gives a framework for managing netfilter, as well as provides a command-line interface for controlling the firewall. It provides user friendly and easy to use interface for Linux newbies who are not much familiar with firewall concepts.

While, on the other side same complicated commands helps administrators it set complicated rules using command line interface. The ufw is an upstream for other distributions such as Debian, Ubuntu and Linux Mint.

Full article here:
How to Install and Configure UFW – An Un-complicated FireWall in Debian/Ubuntu (TecMint)