What is a public cloud?
Public cloud refers to on-demand computing services that are managed by third-party providers, shared by multiple customers, and are accessible via public internet or private network connections.
Why use a public cloud
Enterprises are turning to public cloud for business transformations. Compared to private cloud or on-premise data centers, public cloud provides the following advantages:
No upfront cost, and instead, a pay-as-you-go cost model
No maintenance on facility, hardware, networking, and virtualization technologies
Instant access to global network data centers
Scalability and elasticity to have organic growth or shirk off workloads on demand
Having access to the latest technologies which are unavailable in private cloud or on-premise due to resource constraints
How public clouds work
Public cloud service providers (CSPs) have multinational, high-bandwidth redundant networks connecting data centers across the globe. Underlying resources, such as compute, storage, and networking, are logically isolated to all customers, presented as virtual resources. This type of sharing is called multi-tenancy.
Public CSPs may operate in locally separated locations within the same geographic region. These locations are called availability zones. Each availability zone is inter-connected with high-speed, low-latency networks composed of one or more highly available physical data centers. Using multiple availability zones in the same region gives application resilience within that region.
Enterprises choose public cloud regions and availability zones based on their proximity and data residency compliance requirements.