What is a web application firewall (WAF)?

A web application firewall (WAF) is specifically designed to protect web applications by monitoring and filtering incoming web traffic based on predetermined security rules. It serves as a shield between a web application and the internet, focusing on detecting and blocking malicious requests, such as SQL injection attacks, cross-site scripting (XSS), and other exploits that target vulnerabilities in web applications.

By inspecting HTTP/HTTPS traffic, a WAF can help ensure that only legitimate requests reach the web application server, thus safeguarding sensitive data and maintaining application availability. Its rules can be customized based on the specific needs of the application it protects, providing a highly adaptable layer of security.

In contrast, other options do not align with the primary function of a WAF. For instance, managing user access levels pertains to identity and access management, while encryption tools are focused on protecting data at rest or in transit rather than filtering traffic. Data analysis software, on the other hand, is utilized for analyzing and processing data, which is not related to the security of web applications per se.