What is Public Cloud?

Cloud Deployment Models

Beyond how services are delivered (IaaS, PaaS, SaaS), cloud computing also defines where these services are physically located and who owns and manages the underlying infrastructure.

These are known as cloud deployment models.

Understanding these models helps organizations decide the best fit for their specific security, compliance, and operational needs.

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Public Cloud

The public cloud is the most common and widely recognized form of cloud computing, offering services over the open internet.

Definition:

• A Public Cloud is a type of cloud computing where computing services (like servers, storage, applications) are offered by a third-party provider over the public internet.
• These resources are shared across multiple customers (tenants), but each customer's data and applications are logically isolated.
• The cloud provider owns and manages all the hardware, software, and other supporting infrastructure.

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Key Characteristics:

• Shared Infrastructure: Resources are shared among multiple users or organizations (multi-tenancy).
• High Scalability: The ability to rapidly scale resources up or down to meet demand.
• Pay-as-you-go Pricing: Users pay only for the resources they consume, without upfront capital expenditure.
• Broad Network Access: Services are accessible globally over the internet.
• Managed by Provider: All underlying hardware, software, and maintenance are handled by the cloud provider.

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Customer Control & Management:

• While the cloud provider handles the core infrastructure, customers manage their applications, data, and configuration within their allocated cloud resources.
• This level of control varies based on the chosen service model (IaaS, PaaS, SaaS) within the public cloud.

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Analogy: A Large Public Transportation System Imagine a city's public bus or train system.

Cloud Provider's Role:

• The city (cloud provider) owns and operates all the buses/trains (servers, storage), maintains the roads/tracks (network), and employs the drivers (operations staff).
• They ensure the system is running and available to everyone.

Your Role:

• You (the user) simply purchase a ticket (pay for usage) and ride the bus/train to your destination.
• You share the vehicle with other passengers, but your journey is distinct.
• You don't own the bus or worry about its maintenance; you just use the service.

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Use Cases:

• Websites and Web Applications: Hosting publicly accessible websites, e-commerce platforms, and web applications.
• Development and Testing: Rapidly provisioning environments for software development and testing.
• Big Data Analytics: Processing and storing large datasets using scalable cloud services.
• Disaster Recovery: Setting up backup and recovery sites due to the global presence and redundancy of public clouds.
• General IT Workloads: Any workload that doesn't have strict regulatory or security requirements demanding private infrastructure.

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Quick Note: The "Mass-Market" Cloud

• The public cloud is often considered the "mass-market" cloud.
• It offers unparalleled scalability, cost-effectiveness, and ease of access, making it ideal for a wide range of general-purpose workloads and applications where shared infrastructure is acceptable.
• Major examples include Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).