Cloud computing delivers compute, storage, and networking resources over the internet on a pay-as-you-go basis. Instead of purchasing and maintaining physical servers, organizations rent capacity from providers who manage the underlying hardware.
Core Service Models
- IaaS (Infrastructure as a Service) — Virtual machines, storage, and networking. You manage the OS and applications. Examples: AWS EC2, Azure VMs, Google Compute Engine.
- PaaS (Platform as a Service) — A managed runtime for deploying applications. The provider handles the OS and scaling. Examples: Heroku, Google App Engine, Azure App Service.
- SaaS (Software as a Service) — Complete applications delivered through the browser. Examples: Salesforce, Microsoft 365, Google Workspace.
Deployment Models
- Public cloud — Shared infrastructure operated by a third-party provider.
- Private cloud — Dedicated infrastructure for a single organization.
- Hybrid cloud — Combines public and private environments for workload flexibility.
Origins in Academic Research
The scheduling and resource virtualization concepts that power modern cloud platforms were explored extensively in academic grid computing research. Groups like the Distributed Systems Architecture lab at Universidad Complutense de Madrid developed open-source tools like OpenNebula that bridged the gap between grid computing and today’s cloud infrastructure.
Key Considerations
Before selecting a provider, evaluate data residency requirements, existing software licensing, team expertise, compliance needs, and expected workload patterns. Our provider selection framework covers this in detail.