Tenancy in cloud computing refers to the architectural model that defines how computing resources such as servers, storage, databases, applications, and networks are shared among different customers, known as tenants. A tenant may be an individual, organization, or business that uses cloud services. The tenancy model determines whether resources are dedicated to a single customer or shared among multiple customers while maintaining logical isolation and security. Tenancy is one of the core principles of cloud computing because it directly affects scalability, cost, performance, security, maintenance, and resource utilization. In a cloud environment, service providers allocate resources based on either a Single Tenancy or a Multi-Tenancy model. The choice of tenancy depends on the business requirements, compliance needs, security expectations, and operational costs. The Single Tenancy model provides dedicated infrastructure and application instances to one tenant only. Each customer has separate computing resources, storage, databases, and sometimes even dedicated physical servers. Since resources are not shared with other customers, there is a high level of isolation, reducing the risk of data leakage and unauthorized access. This model offers better control over system configurations, security policies, and software customization. Organizations dealing with highly sensitive information such as financial institutions, government agencies, and healthcare providers often prefer Single Tenancy because it simplifies compliance with regulatory standards. However, the model increases infrastructure costs because resources remain dedicated even during periods of low utilization. It also requires more maintenance and administrative effort from the cloud provider. The Multi-Tenancy model allows multiple tenants to