The CSM position is now attracting attention with the rise of the cloud movement, and a new trend in the non-IT business of unlimited use of services with a fixed monthly fee is spreading, as is the “don’t own it, just use it” style of IT. There is a shift from installing software on a PC or purchasing a server, installing applications on it, and running the software yourself, to installing only a browser and then using the services on a subscription basis. This style has already become the norm, and from the standpoint of security, the idea of storing data on your PC is already a thing of the past. Service providers, on the other hand, are beginning to realize the importance of follow-up after the sale, as they switch from a “sold out type model” to a “subscription” revenue stream. Many service providers are now urgently seeking to fill the new position of “Customer Success Manager” (CSM), a position that specializes in long term support of the customer after contract. This course is like a “CSM textbook” for those who are interested in CSM, those who are looking for a CSM as a service provider, and those who want to learn what CSM itself is all about. This is a “CSM textbook” for those who are interested in CSM, those who are looking for CSM as a service provider, and those who want to learn what CSM itself is all about. The course is designed to be as easy to understand as possible with diagrams and illustrations so that those who want to learn about cloud computing can understand the key points of cloud computing business by understanding the position of CSM.