A Cloud Service Provider (CSP) is an organization that provides cloud computing services such as Infrastructure as a Service, Platform as a Service, and Software as a Service. CSPs are responsible for managing the physical infrastructure and providing access to the cloud service.
An MSP is an organization that provides remote management and monitoring of an organization's IT infrastructure, applications, and data. MSPs provide advice and support for hardware, software, network, and security needs. They are responsible for the day-to-day maintenance, management, and monitoring of an organization's IT environment, including hardware, software, applications, and data.