Is iptables a service running with ufw or can i run it as standalone without ufw.In the result of sudo iptables -L there are chains of ufw also,so what is the difference between the input,output and forward chains of iptables and chains of ufw .Is there any good material online for this .Please help..
The following wiki touches a bit about iptables, netfilter, and ufw.
https://wiki.ubuntu.com/UncomplicatedFirewall
Here's a short quote: