Which cloud type allows multiple tenants to share computing resources outside their firewalls?

The correct answer is public cloud. A public cloud is designed to allow multiple tenants, or users, to share computing resources such as servers and storage over the internet. In a public cloud model, the infrastructure and services are hosted off-premises by a cloud provider, and customers access these resources through the internet. This model provides scalability and flexibility, as users can increase or decrease their usage based on demand without the need to manage the underlying hardware.

Public clouds are typically cost-effective because they operate on a pay-as-you-go basis, eliminating the need for organizations to invest in their own infrastructure. By sharing resources, multiple organizations benefit from the economies of scale that public cloud providers capitalize on, leading to lower costs per user.

For contrast, a private cloud is dedicated to a single organization, providing greater control and security, but it does not allow multiple tenants to share resources in the same way. Similarly, a community cloud is shared among a specific group of organizations with common interests, while a hybrid cloud combines both public and private clouds, enabling data and applications to be shared between them—but only the public cloud configuration allows for broad tenant sharing without the constraints of firewalls typically found in private configurations.