In the client-server model what is the primary protocol used for communication between a browser and web server?

The primary protocol used for communication between a browser and a web server in the client-server model is HTTP (Hypertext Transfer Protocol). HTTP allows clients (browsers) to send requests to the server for resources like web pages, images, and other content, and for the server to respond with the requested data. Secure versions of this protocol, such as HTTPS, use encryption to protect the data exchanged between the client and server.