Which of the following protocols operates at the Application layer?

HTTP, which stands for Hypertext Transfer Protocol, operates at the Application layer of the OSI model. This layer is responsible for providing end-user services and network application support. HTTP is specifically designed to facilitate communication between web browsers and servers, allowing users to retrieve and display web content.

The Application layer protocols, like HTTP, focus on the interaction between the software applications and the network, enabling functionalities like web browsing, email communication, and file transfers. Because HTTP directly supports the operations and needs of end-user applications (such as web browsers), it is categorized at this layer.

On the other hand, TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) operate at the Transport layer, which is responsible for ensuring data is transported reliably or quickly, without focusing on the content. IP (Internet Protocol) works at the Network layer, handling the routing of packets across networks without an understanding of the data being transferred. This differentiation helps clarify the role each protocol plays within the networking stack.