A Web Application Firewall (WAF) is a security solution designed to protect web applications by monitoring, filtering, and blocking malicious traffic between the internet and the application. It acts as a barrier, analyzing incoming and outgoing data to detect and prevent common cyber threats such as SQL injection, cross-site scripting (XSS), and other vulnerabilities. By identifying suspicious patterns and blocking harmful requests, a WAF helps safeguard sensitive data, maintain website availability, and ensure compliance with security standards. WAFs can be hardware-based, software-based, or cloud-based, and are an essential part of modern web security strategies.