The main cloud deployment models are public cloud, private cloud, hybrid cloud and multi cloud.
Public cloud:
Public clouds are the most common way of deploying cloud computing. The cloud resources (like servers and storage) are owned and operated by a third-party cloud service provider and delivered over the Internet. Oracle Cloud Infrastucture (OCI)/ AWS/Microsoft Azure are examples of a public cloud. With a public cloud, all hardware, software, and other supporting infrastructure is owned and managed by the cloud provider. In a public cloud, you share the same hardware, storage, and network devices with other organizations or cloud “tenants.” You access services and manage your account using a web browser. Public cloud deployments are frequently used to provide web-based email, online office applications, storage, and testing and development environments. Public clouds include SaaS, PaaS, and IaaS services
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 computing resources used exclusively by one business or organization. The private cloud can be physically located at your organization’s on-site datacenter, 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 solely 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.
- Improved security – resources are not shared with others, so higher levels of control and security are possible.
- High scalability – private clouds still afford the scalability and efficiency of a public cloud.
Hybrid cloud:
A cloud that combines in some form resources from a public cloud and a private cloud.
Advantages of hybrid clouds:
- Control – your organization can maintain a private infrastructure for sensitive assets.
- 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.
Multi cloud: Use of more than one cloud service of the same type (public/private) in a single solution, sourced from different vendors.
Multi Vs Single Tenancy Cloud:
Multi-tenant Software as a Service (SaaS) is an architecture where multiple companies share the same instance to store their data. Multi-tenancy means that a single instance of the software and all of the supporting infrastructure serves multiple customers. Each customer shares the software application and also shares a single database. The data is tagged in the database as belonging to one customer or another, and the software is smart enough to know who the data belongs to.
Single-tenant (or hosted) Software as a Service (SaaS) is an architecture where each company has their own
instance of the software application and supporting infrastructure. A single instance of the software and all of the supporting infrastructure serves a single customer. With single tenancy, each customer has their own independent database and instance of the software. With this option, there’s essentially no sharing going on. Everyone has their own, separate from everyone else.