# Firewalls Concepts

DigitalOcean Cloud Firewalls are a network-based, stateful firewall service for Droplets provided at no additional cost. Cloud firewalls block all traffic that isn’t expressly permitted by a rule.

[How to Organize DigitalOcean Cloud Firewalls](https://docs.digitalocean.com/products/networking/firewalls/concepts/organization/index.html.md): Organize cloud firewalls by role and resource tag to simplify management and maintain clear security boundaries as your infrastructure scales.

[What is a Firewall and How Does It Work?](https://www.digitalocean.com/community/tutorials/what-is-a-firewall-and-how-does-it-work): This community tutorial covers how firewalls work, with a focus on stateful software firewalls (like iptables and FirewallD) as they relate to cloud servers

[How To Choose an Effective Firewall Policy to Secure your Servers](https://www.digitalocean.com/community/tutorials/how-to-choose-an-effective-firewall-policy-to-secure-your-servers): Using a firewall is as much about making intelligent policy decisions as it is about learning the syntax. This community tutorial covers decisions you must make when implementing a firewall. These choices affect how your firewall behaves, how locked down your server is, and how it will respond to various common situations. This tutorial uses iptables as an example, but the decisions are relevant regardless of the tools used.