What is a WAF? (Web Application Firewall)

A WAF (Web Application Firewall) is a firewall designed to specifically protect web applications from HTTP/S (Layer 7) attacks. This is achieved by monitoring the data transferred between the client and the web application. If the client tries to send any data with malicious intent the WAF will terminate the connection. A WAF can be used as a reverse proxy to ensure that there is no direct connection between the client and web application, further increasing the security of the connection.