A web application firewall (WAF) is specifically designed to monitor, filter, and block HTTP traffic to and from a web application. It is different from other types of firewalls because it can filter the content of specific web applications. By inspecting HTTP traffic, a WAF can prevent attacks stemming from web application security flaws, such as SQL injection and cross-site scripting (XSS), file inclusion, and security misconfigurations.

References: The use of WAFs to block XSS and SQL injection attacks is well-documented in cybersecurity literature. They are recognized for their ability to perform a detailed inspection of HTTP traffic, applying rules to an HTTP conversation to cover a wide range of security issues, including XSS and SQL injection, which are not typically covered by other firewall types12.