“Public cloud” or “Cloud computing” is a model of delivering Hosted Services provided by Service Providers over the internet. Service provider makes resources, such as virtual machines (VMs), applications or storage, available to the general public over the internet.
Public Cloud providers have a multi-tenant architecture that enables users or tenants to share computing resources. Each tenant's data in the public cloud, however, remains isolated from other tenants.
In public clouds although the resources are shared between multiple clients but all the services are controlled by services provider.
Organizations that are fully dependent on IT to meet business goals have understood the value of cloud computing for its availability, scalability, instant provisioning, virtualized resources and storage.
Public cloud architecture can be further categorized by service model. Common service models include:
Software as a service (SaaS)
A third-party Service provider hosts applications and makes them available to customers over the internet.
Platform as a service (PaaS)
A third-party Service provider delivers hardware and software tools usually needed for application development to its users as a service.
Infrastructure as a service (IaaS)
A third-party Service provider offers virtualized computing resources such as VMs and storage over the internet.
Benefits of Public Cloud:
Simple and easy:
Public clouds are available as a service in the internet, they are easy to deploy.
Low Initial Cost:
Initial investment (CAPEX) is very low or nil.
Less time to Delivery
The IT resources and services are available immediately saving time for the company.
The hardware and networks are maintained by the cloud services provider. Internal IT staffs have no responsibility in maintaining the infrastructure.
No long term commitment with service provider because public clouds are usually pay-as-you-go models.
Public Cloud is suitable When:
Cloud adoption has just started in the organization.
Business growth is dynamic, tied to seasonality and promotional offerings
Capital dollars(CAPEX) for hardware purchases are limited
Highly variable workloads
Suitable for SaaS applications like Office 365.
On Demand Work Loads or Projects are regular
Assess Customer IT environment and determine the data and apps that are viable for Public Cloud migrations
Provide a Road Map for Cloud adoption and provide TCO and ROI for moving Apps to Public Cloud
Help our customers with staging, testing, and validation before moving their production environments to Public Cloud
Offer support while delivering on SLAs and uptime guarantees
Operates and Monitors Customer Cloud Environment (Public and Hybrid) with governance over their Cloud usage by managing their billing and Cloud capacity planning