NPSP is part of the nonprofit cloud. NPSP provides the data architecture that sits on top of Sales Cloud and is pre-configured for the use cases most nonprofits need, such as donation management, Household model, Accounting units, etc. The nonprofit cloud, on the other hand, provides much more. It provides a complete set of Salesforce products, such as Sales Cloud, Marketing Cloud, Communities, etc., to address the technology challenges that nonprofits face.