A firewall is a security system that monitors and filters incoming and outgoing network traffic, blocking anything that looks malicious or unauthorized while letting legitimate traffic through. Think of it as a checkpoint sitting between a website and the wider internet, inspecting everything trying to pass through.
Types Relevant to a Website
- Network firewalls — protect an entire server or network infrastructure
- Web Application Firewalls (WAF) — specifically filter traffic aimed at a website or web app
- Software firewalls — run directly on an individual server or device
What a Firewall Actually Blocks
- Known malicious IP addresses and bot traffic
- SQL injection attempts targeting a site's database
- Cross-site scripting (XSS) attacks
- Brute-force login attempts
- DDoS traffic aimed at overwhelming a server
Firewall Options for WordPress
- Sucuri — a well-regarded security plugin with a strong built-in firewall
- Wordfence — a very widely used security and firewall plugin
- Cloudflare — offers firewall protection at the network level, before traffic even reaches your server
For any site handling sensitive data or user accounts, a firewall isn't optional — it's one of the most basic and effective layers of protection against the constant background noise of automated attacks every website on the internet faces.
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