Abstract- Software as a Service (SAAS) applications delivered via the cloud is the most popular services in the cloud, particularly for multi-tenancy. Multi-tenancy refers to the sharing of computer resources with other users. Multitenant architecture is commonly used in public clouds. When offering services to vendors, cloud providers are asked questions about performance evaluation and data security. The many types of multi-tenancy, various authentication and authorization techniques, as well as the idea of least privileges, are all discussed. This article provides the reader with a clear image of how to pick the right multi-tenancy environment and authorization method for their SAAS applications, as well as data on authentication and authorization in the Azure cloud.