Tell about WAF (Web Application Firewall) — what it is and how it works?

WAF (Web Application Firewall) is a specialized firewall that filters, monitors, and blocks HTTP traffic to web applications to protect against attacks.

How WAF works:

• Analyzes incoming requests for known threats (SQL injections, XSS, CSRF, session attacks, etc.).
• Applies security rules and policies, which can be static (a set of rules) or dynamic (learning from behavior).
• Blocks or modifies suspicious traffic before it reaches the web application.

Example: if a SQL injection attempt is detected in a request, WAF can block the request, send a warning, or replace malicious parts.

WAF helps protect web applications from vulnerabilities that may not be closed at the code or infrastructure level and is an important element of comprehensive security.