What is Public Cloud?
A public cloud is a computing model where third-party providers make shared infrastructure resources such as servers, storage, and networking available to multiple tenants over the public internet.
A public cloud is a deployment model in which cloud infrastructure is owned and operated by a third-party service provider and delivered over the public internet to any paying customer. Resources are pooled across a large, multi-tenant environment. The provider manages all underlying hardware, hypervisors, and operational software. Customers provision virtual machines, storage buckets, databases, or serverless functions on demand, paying only for what they use. The defining characteristics are shared infrastructure, internet-based access, and provider-managed operations.
In a public cloud, the provider abstracts physical hardware into a virtualized pool. Each tenant's workloads are isolated through software-defined networking, virtual LANs, identity and access management, and hypervisor-level partitioning. Providers maintain massive data centers across regions and availability zones, and they offer self-service consoles, APIs, and CLI tools for resource management. Services are typically billed on a consumption basis per hour, per gigabyte, or per request. Examples include Amazon Web Services (AWS) Elastic Compute Cloud (EC2), Microsoft Azure Virtual Machines, and Google Compute Engine.
Compared to private cloud or on-premises infrastructure, the public cloud model eliminates capital expenditure on hardware and reduces operational overhead for maintenance, patching, and cooling. However, it introduces shared responsibility for security: the provider secures the cloud infrastructure, while the customer must secure their data, configurations, and access policies. Public clouds are widely used for web applications, development and test environments, disaster recovery, big data analytics, and variable-load workloads that benefit from rapid elasticity.
Key facts
- Multi-tenant architecture shares physical infrastructure across many customers.
- Provider owns and manages all hardware, networking, and data center facilities.
- Customers access resources via public internet or dedicated connections.
- Billing is based on consumption metrics such as compute hours, storage GB, or API calls.
- Offers rapid elasticity, allowing near-instant scaling of resources up or down.
How it works in practice
Related terms
References
More in Cloud Computing
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