When your DNS records are [proxied](https://developers.cloudflare.com/dns/proxy-status/) through Cloudflare, Cloudflare provides free and unmetered DDoS protection and other protection measures through the Web Application Firewall (WAF).

## DDoS protection

A distributed denial-of-service (DDoS) attack is where a large number of computers or devices, usually controlled by a single attacker, attempt to access a website or online service all at once. This flood of traffic can overwhelm the website's origin servers, causing the site to slow down or even crash.

```mermaid
sequenceDiagram;
    participant User;
    participant Website;
    participant Server;
    participant Botnet;
    User->>Website: Requests to access site
    Website->>Origin Server: Processes user requests
    Botnet->>Origin Server: Sends a flood of traffic
    Origin Server-->>Website: Slows down due to traffic overload
    Origin Server-->>User: Unable to respond to user requests
```



For more information about DDoS attacks and Cloudflare DDoS protection, refer to [Prevent DDoS attacks](https://developers.cloudflare.com/learning-paths/personal-website/concepts/).

## Managed rulesets

All customers have access to the Cloudflare Free Managed Ruleset, which provides mitigations against high and wide-impacting vulnerabilities.

For more details, refer to the [WAF documentation](https://developers.cloudflare.com/waf/managed-rules/).
