Application Level Firewall
With an application-level firewall, you examine the traffic after it reaches your server but before loading most WordPress scripts. Compared to a DNS-level firewall, an application firewall is not as efficient when it comes to reducing the server load.
A DNS-level firewall is exceptionally good at discerning genuine traffic from vulnerable requests. They do that by learning from thousands of websites, comparing trends, preventing known bad IPs, and blocking traffic to pages that your users would normally never request.