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What is public cloud?

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Public cloud is an IT model where on-demand computing services and infrastructure are managed by a third-party provider and shared with multiple organizations using the public Internet. Public cloud service providers may offer cloud-based services such as infrastructure as a service (IaaS), platform as a service (PaaS), or software as a service (Saas) to users for either a monthly or pay-per-use fee, eliminating the need for users to host these services on site in their own data center


Cloud service providers use groups of data centers that are partitioned into virtual machines and shared by tenants. Tenants may simply rent the use of those virtual machines, or they may pay for additional cloud-based services such as software applications, application development tools, or storage. Companies often use public cloud services for less-sensitive applications that have unpredictable spikes in usage or for storing data that does not require frequent access.


Public cloud makes computing resources available to anyone for purchase. Multiple users typically share the use of a public cloud. In contrast, private cloud involves cloud-based services that are hosted within an organization’s own private servers. 



Definition of public cloud

Public cloud is a cloud deployment model where computing resources are owned and operated by a provider and shared across multiple tenants via the Internet.



Why public cloud?

Many enterprise businesses look to public cloud as a way to scale existing IT resources on demand without committing to expanding their physical IT infrastructure. For instance, instead of purchasing a physical desktop machine, a company can purchase a virtual desktop license. The virtual desktop can be spun up or deactivated in minutes and can be located anywhere, instantly.

The public cloud is also a popular solution for storage needs since data stored on a public cloud is backed up and accessible from anywhere. There are many different types of storage plans, and data that does not need to be accessed frequently can often be stored in the public cloud very cheaply.

For companies that host an application with periods of peak usage, the public cloud makes perfect sense because the extra computing power is only needed for a short time.


Using the public cloud can save businesses money in a couple of different ways: 

  • Lower equipment purchase costs: Because employees can access and pay for cloud-based resources only when they need them, using public cloud–based desktops and applications is often less expensive than purchasing physical IT equipment or software packages that may or may not be used and will need to be maintained. 
  • Lower equipment maintenance costs: With public cloud-based services, the cost of maintaining IT equipment is also passed on to the cloud service provider.

A small or new business may have an easier time migrating applications to the public cloud; organizations with a large legacy IT infrastructure and applications have more to consider and plan for. However, more and more enterprise businesses are moving toward public cloud as one element of a multi-faceted IT plan. This way, they can access the benefits of public cloud while also maintaining the different benefits that come with on-premises architecture and private cloud options.



How public cloud works

A public cloud relies on a virtualized environment to provide an extension of a company’s IT infrastructure, allowing that company to host certain aspects of its infrastructure and services on virtual servers that are offsite and owned by a third party. Public cloud service providers have different strengths, and they offer a wide variety of services and pricing models. Companies that are considering a migration to public cloud need to carefully consider their options when it comes to choosing a provider, especially if they will be locked into a long-term contract. Careful planning can help to keep costs down on monthly cloud services bills, but organizations with unpredictable public cloud usage may find it hard to avoid spending a lot of money on public cloud services when usage suddenly surges. 


Because servers in the public cloud share data from multiple companies, security in public cloud is another issue that IT managers will want to weigh. Encrypting data is a good way to ensure stronger security, but if you are using a combination of public and private cloud (also known as a hybrid cloud), not all encryption platforms work across both public and private clouds. There is also an inherent security risk whenever data is moved between a private data center or private cloud and a public cloud.


One last consideration is the location of your public cloud service provider. Data privacy laws in many countries require certain types of data to be stored in-country. These laws change frequently, so it’s a good idea to choose a cloud service provider that is located in your country and can confirm that the servers where your data will be stored are local and in compliance with regional laws. There is also the issue of latency—if your data is being hosted on a different continent, it may take longer than if it were stored close by.



Public cloud vs private cloud vs hybrid cloud

A company that needs cloud computing services can choose to use a public cloud (where cloud services are hosted by a cloud service provider and shared with other tenants), a private cloud (where cloud services are hosted by the company itself), or a combination of the two, known as a hybrid cloud.

Public cloud offers the advantage of easy scalability. Although a private cloud is less expensive than using a public cloud (after an initial investment in the infrastructure), it doesn’t scale as easily. Growing the infrastructure can require the purchase of additional equipment. If usage of the private cloud shrinks, expensive resources and equipment become underutilized.

Hybrid cloud can be a great compromise for those considering public cloud vs private cloud. Hybrid cloud refers to any combination of private and public cloud solutions. A hybrid cloud environment allows organizations to benefit from the advantages of both types of cloud platforms and choose which cloud to use based on specific data needs. For instance, hybrid cloud provides an alternative for storing sensitive data—a company might provide services via a public cloud while keeping sensitive information on a private cloud.


Related Topics
Private Cloud
Hybrid Cloud
Cloud Cost Management
Kubernetes 
Private Cloud Solutions
Multi-Cloud


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