As Gartner defined, Secure Web Gateways utilize URL filtering, advanced threat defense, legacy malware protection and application control technologies to defend users from Internet-borne threats, and to help enterprises enforce Internet policy compliance. SWGs are delivered as on-premises appliances (hardware and virtual) or cloud-based services. Vendors differ greatly in the maturity and features of their cloud-based services, and in their ability to protect enterprises from advanced threats.
Let's assume that I have a Firewall, IPS on my network and Web Application Firewall in front of my Web Applications, Server.
I know that Next Generation Firewall's now provide URL Filtering, Application Control, Antivirus and so on. WAF will secure the back end web server by monitoring every HTTP request and response to and from the server. So, I'm confused on,
What would be the protection that Secure Web Gateway only provides, other appliances don't?