According to the National Institute of Standards and Technology (NIST), which is a primary source for cloud computing standards and guidelines, the five main actors in cloud computing are Consumer, Provider, Carrier, Auditor, and Broker. These roles are defined as follows:

Consumer: The person or organization that uses cloud computing services.

Provider: The entity that provides the cloud services to consumers.

Carrier: The organization that offers connectivity and transport services to cloud providers and consumers.

Auditor: An independent party that assesses and verifies the cloud services, security controls, and operations.

Broker: An entity that manages the use, performance, and delivery of cloud services, and negotiates relationships between cloud providers and consumers.

These actors play critical roles in the ecosystem of cloud computing, ensuring the services are delivered and used securely, efficiently, and effectively.