How does a web application firewall (WAF) differ from a standard firewall?

A web application firewall (WAF) is specifically designed to protect web applications by filtering and monitoring HTTP traffic that goes to and from those applications. Its primary function is to inspect incoming requests to identify and block malicious traffic that could exploit vulnerabilities in web applications, such as SQL injection or cross-site scripting (XSS). By focusing on the application layer (Layer 7 of the OSI model), a WAF can offer detailed security tailored to the specific behaviors of web traffic.

In contrast to standard firewalls, which typically monitor network traffic at lower layers and manage connections more broadly across the network, a WAF operates at a higher level and employs rules specific to web application security. This makes it especially effective for preventing attacks that are specifically aimed at the application itself, as opposed to just controlling access between networks.