This lecture covers the fundamentals of cloud remote procedure calls (RPCs) and their significance in modern software architecture. It begins with an overview of how web-based and mobile applications communicate with cloud services, emphasizing the importance of understanding the underlying architecture. The instructor introduces key terminology and concepts related to RPCs, including synchronous and asynchronous communication, client-server interactions, and the various protocols used in cloud services. The lecture also discusses the implications of server performance and location on RPC efficiency, highlighting the need for effective client authentication and authorization. Two case studies are presented to illustrate the practical applications of cloud RPCs, demonstrating how they can be utilized in real-world scenarios. The session concludes with a summary of best practices for designing and implementing cloud RPCs, ensuring that students grasp the essential components required for successful cloud-based communication.