Learning Goals

• Define the purpose of the application layer within a layered network architecture.
• Identify how application-layer services interact with transport-layer protocols to support end-user communication.
• Classify common network applications according to their communication model, service requirements, and protocol dependencies.
• Describe the difference between a network service and a protocol using concrete examples from the module.
• Map typical user activities such as browsing, emailing, remote login, and file transfer to the corresponding application-layer protocols.