A Web application firewall (WAF) is a feature that a web application developer can add to the source code of his or her web application.
WAF is usually referred to as "Web Application Firewall" (WAF) in Web application development jargon.
The WAF application acts as a filter on the Internet traffic that enters your server and this means that you do not have to worry about the security of your Internet traffic.
When your application is developed in a secure environment, it allows your website to be accessed using a secure protocol that cannot be compromised.
Another important reason why WAF should be installed on your server is that it gives you the opportunity to protect your clients from any unwanted software intrusion in the security of your website.
For instance, if a malicious software is used to hack into your server, the protection provided by your WAF may help you defend your website from further attacks.