HeatShield is a Web Application Firewall for WordPress sites hosted on cloud servers.
HeatShield separately makes available free SSH brute force login protection to simplify a common security need of cloud servers.
HeatShield's WordPress Firewall is a WordPress plugin that secures your site with an advanced Web Application Firewall (WAF) built on ModSecurity, the industry-standard WAF engine.
The WAF analyzes the content of every request to your site and rejects requests that are malicious, such as requests performing XSS, SQL injection, and code injection attacks as well as attempts to exploit vulnerable plugins.
HeatShield's WordPress plugin also offers free WordPress login brute force protection.
Unrelated to WordPress, HeatShield also offers free SSH brute force login protection as an optional additional layer of security for your cloud servers.
You do not need to use SSH brute force login protection to use HeatShield's WordPress Firewall.
When you use SSH brute force protection, HeatShield configures an IP Packet Filter on your server that allows only SSH, HTTP, and HTTPS traffic into your server.