The Uncomplicated Firewall (ufw) is a frontend for iptables and is particularly well-suited for host-based firewalls.
Get all rules:
ufw status numbered
Output:
Status: active
To Action From
-- ------ ----
[ 1] 80/tcp ALLOW IN Anywhere
[ 2] 443/tcp ALLOW IN AnywhereDelete rule:
ufw delete 2