Types of Cloud Computing

 There are two type of cloud computing

• Deployment model
• Public
• Private
• Hybrid
• Service Model
• IAAS (Infrastructure as a Service)
• PAAS (Platform as a Service)
• SAAS (Software as a Service)
• Deployment model
• A deployment model refers to the type of architecture in which cloud services are implemented and delivered. It defines how the cloud infrastructure is set up, who has access to it, and the level of control over the hardware, software, and network resources.
• Public cloud:

• Public clouds are the most common type of cloud computing deployment.
• The cloud resources (like servers and storage) are owned and operated by a third-party cloud service provider and delivered over the internet.
• With a public cloud, all hardware, software, and other supporting infrastructure are owned and managed by the cloud provider.
• Microsoft Azure is an example of a public cloud.
• In a public cloud, you share the same hardware, storage, and network devices with other organizations or cloud “tenants,” and you access services and manage your account using a web browser.
• Advantages of Public cloud:
• Lower costs—no need to purchase hardware or software, and you pay only for the service you use.
• No maintenance—your service provider provides the maintenance.
• Near-unlimited scalability—on-demand resources are available to meet your business needs.
• High reliability—a vast network of servers ensures against failure.
• Private Cloud:

• A private cloud consists of cloud computing resources used exclusively by one business or organization.
• The private cloud can be physically located at your organization’s on-site datacentre, or it can be hosted by a third-party service provider.
• But in a private cloud, the services and infrastructure are always maintained on a private network and the hardware and software are dedicated exclusively to your organization.
• In this way, a private cloud can make it easier for an organization to customize its resources to meet specific IT requirements.
• Private clouds are often used by government agencies, financial institutions, any other mid- to large-size organizations with business-critical operations seeking enhanced control over their environment.
• Advantages of a private cloud:
• More flexibility—your organization can customize its cloud environment to meet specific business needs.
• More control—resources are not shared with others, so higher levels of control and privacy are possible.
• More scalability—private clouds often offer more scalability compared to on-premises infrastructure.
• Hybrid Cloud:

• A hybrid cloud is a type of cloud computing that combines on-premises infrastructure—or a private cloud—with a public cloud.
• Hybrid clouds allow data and apps to move between the two environments.
• Many organizations choose a hybrid cloud approach due to business necessities such as meeting regulatory and data control requirements, taking full advantage of on-premises technology investment, or addressing low potential issues.
• The hybrid cloud is evolving to include edge workloads as well.
• Edge computing brings the computing power of the cloud to IoT devices—closer to where the data resides.
• By moving workloads to the edge, devices spend less time communicating with the cloud, reducing latency, and they are even able to operate reliably in extended offline periods.
• Advantages of the hybrid cloud:
• Control—your organization can maintain a private infrastructure for sensitive assets or workloads that require low latency.
• Flexibility—you can take advantage of additional resources in the public cloud when you need them.
• Cost-effectiveness—with the ability to scale to the public cloud, you pay for extra computing power only when needed.
• Ease—transitioning to the cloud doesn’t have to be overwhelming because you can migrate gradually—phasing in workloads over time.
• Service Model:
• A service model defines the level of control and management responsibility shared between the cloud provider and the customer. It outlines the specific services offered and determines how much control a user has over the underlying infrastructure.

• IAAS, or infrastructure as a service:

• IAAS is on-demand access to cloud-hosted physical and virtual servers, storage and networking—the backend IT infrastructure for running applications and workloads in the cloud.
• IaaS is also known as Hardware as a Service (HaaS). It is a computing infrastructure managed over the internet. The main advantage of using IaaS is that it helps users to avoid the cost and complexity of purchasing and managing the physical servers.
• Characteristics of IaaS:
• Resources are available as a service
• Services are highly scalable
• Dynamic and flexible
• GUI and API-based access
• Automated administrative tasks
• Benefits of IaaS:
• Higher accessibility:
• With IaaS a company can create redundant servers easily, and even create them in other geographies to ensure availability during local power outages or physical disasters.
• Lower potential, improved performance:
• Because IaaS providers typically operate data centers in multiple geographies, IaaS customers can locate apps and services closer to users to minimize latency and maximize performance.
• Improved responsiveness:
• Customers can provision resources in a matter of minutes, test new ideas quickly and quickly roll out new ideas to more users.
• Comprehensive security:
• With a high level of security onsite, at data centres, and via encryption, organizations can often take advantage of more advanced security and protection they might provide if they hosted the cloud infrastructure in-house.
• Faster access to best-of-breed technology:
• Cloud providers compete with each other by providing the latest technologies to their users, IaaS customers can take advantage of these technologies much earlier (and at far less cost) than they can implement them on premises.
• PaaS, or platform as a service:

• PAAS is on-demand access to a complete, ready-to-use, cloud-hosted platform for developing, running, maintaining and managing applications.
• PaaS cloud computing platform is created for the programmer to develop, test, run, and manage the applications.
• Characteristics of PaaS:
• Accessible to various users via the same development application.
• Integrates with web services and databases.
• Builds on virtualization technology, so resources can easily be scaled up or down as per the organization's need.
• Support multiple languages and frameworks.
• Provides an ability to "Auto-scale".
• Benefits of PaaS:
• Faster time to market:
• PaaS enables development teams to spin-up development, testing and production environments in minutes, rather than weeks or months.
• Low- to no-risk testing and adoption of new technologies:
• PaaS platforms typically include access to a wide range of the latest resources up and down the application stack.
• This allows companies to test new operating systems, languages and other tools without having to make substantial investments in them, or in the infrastructure required to run them.
• Simplified collaboration:
• As a cloud-based service, PaaS provides a shared software development environment, giving development and operations teams access to all the tools they need, from anywhere with an Internet connection.
• A more scalable approach:
• With PaaS, organizations can purchase extra capacity for building, testing, staging and running applications whenever they need it.
• Less to manage:
• PaaS offloads infrastructure management, patches, updates and other administrative tasks to the cloud service provider.
• SaaS, or software as a service:

• SAAS is on-demand access to ready-to-use, cloud-hosted application software.
• SaaS is also known as "on-demand software".
• It is a software in which the applications are hosted by a cloud service provider.
• Users can access these applications with the help of internet connection and web browser.
• Characteristics of SaaS:
• Managed from a central location
• Hosted on a remote server
• Accessible over the internet
• Users are not responsible for hardware and software updates. Updates are applied automatically.
• The services are purchased on the pay-as-per-use basis
• Benefits of SaaS:
• Minimal risk:
• Many SaaS products offer a free trial period, or low monthly fees that let customers try the software to see if it will meet their needs, with little or no financial risk.
• Anytime/anywhere productivity:
• Users can work with SaaS apps on any device with a browser and an internet connection.
• Easy scalability:
• Adding users is as simple as registering and paying for new seats—customers can purchase more data storage for a nominal charge.

Difference between Public vs Private clouds

Feature	Public Cloud	Private Cloud
Definition	Services offered over the internet by third-party providers to multiple users.	Cloud infrastructure dedicated to a single organization.
Ownership	Owned and operated by third-party providers.	Owned and operated by the organization itself or a third-party vendor but dedicated to a single organization.
Cost	Pay-as-you-go pricing model; often lower initial cost.	Higher initial cost due to hardware and software investments.
Scalability	Highly scalable with virtually unlimited resources.	Limited by the organization’s infrastructure, though can be scalable within those limits.
Control	Limited control over infrastructure and resources.	Full control over infrastructure, resources, and security.
Security	Shared infrastructure might lead to security concerns; providers offer robust security measures.	Higher security as resources are not shared; customizable security policies.
Performance	May be affected by other users (multi-tenancy)	Consistent performance since resources are dedicated.
Compliance	May face challenges meeting specific compliance requirements.	Easier to comply with industry-specific regulations and standards.
Maintenance	Managed by the cloud service provider.	Managed by the organization’s IT staff or a third-party vendor.
Examples	Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP).	VMware Private Cloud, OpenStack, Microsoft Azure Stack.
Use Cases	Startups, development and testing environments, applications with unpredictable workloads.	Large enterprises, sensitive data processing, applications with predictable workloads.