Public Cloud is a platform that uses a standard cloud computing model to make resources, such as virtual machines (VMs), applications or storage, available to users remotely. Public cloud services can be free or offered through a variety of subscription or on-demand pricing schemes, including pay-per-use models.
The main benefits of public cloud services are:
- This reduces the need for organizations to invest and maintain their own local IT resources.
- This allows scalability to meet workloads and user requests; and
- There are fewer resources wasted because customers only pay for what they use.
History of Public Cloud
While the concept of cloud computing has existed since the 1960s, it did not reach public popularity for companies until the 1990s. Salesforce, which is now the top software provider as a service provider (SaaS), entered the market in 1999 by sending applications through its website. Soon followed by browser-based applications, such as G Suite, which can be accessed by many users.
In 2006, retail company Amazon launched Elastic Compute Cloud (EC2), its infrastructure as a service platform (IaaS), for general use. Under its cloud division, Amazon Web Services (AWS), companies can “rent” virtual computers but use their own systems and applications. Soon after, Google released Google App Engine, its platform as a service (PaaS) service, for applications that were developed and Microsoft came out with Azure, also the PaaS offer. Overtime, the three of them built the IaaS, PaaS, and SaaS offers. Even old hardware vendors entered the market, such as IBM and Oracle.
However, not all vendors who try to compete successfully. Verizon, HPE, Dell, VMware, and others are forced to close their public clouds, often refocusing on hybrid clouds.
Public Cloud Architecture
Public cloud is a fully virtualized environment. In addition, providers have a multi-tenant architecture that allows users – or tenants – to share computing resources. But each tenant’s data in the public cloud, remains isolated from other tenants. Public cloud also relies on high bandwidth network connectivity to transmit data quickly.
Public cloud storage is usually redundant, using multiple data centers and careful file version replication. This characteristic has given him a reputation of endurance.
Public cloud architecture can be further categorized based on service models. General service models include:
- Software as a service (SaaS), where a third party provider organizes an application and makes it available to customers via the internet;
- Platform as a service (PaaS), in which a third party provider provides hardware and software – usually needed for application development – to its users as a service; and
- Infrastructure as a service (IaaS), where third-party providers offer virtual computing resources, such as VMs and storage, via the internet or through special connections.
Difference Between Public and Private Clouds
The term public cloud appears to distinguish between the standard cloud computing model and the private cloud, which is an exclusive cloud computing architecture dedicated to one organization. Private cloud is different from public cloud, because it functions as an extension of an existing corporate data center and can only be accessed by that company.
The third model, hybrid cloud, is managed by internal and external providers. As a result, hybrid cloud is a combination of public and private cloud services, with orchestration between the two. In some cases, this model is interesting because it allows organizations to utilize the benefits of public cloud, while maintaining their own private cloud for sensitive, critical or highly regulated data and applications. The fourth option is a multi-cloud architecture where companies use more than one cloud. Most often it refers to the use of several public clouds.
Public Cloud Pros And Cons of Pricing
In general, public cloud is seen as a way for companies to increase IT resources on demand, without having to maintain as many infrastructure components, applications, or development resources at home.
Public Cloud Security
Due to the multi-tenant nature of public cloud, security is a continuing concern for several companies. Public cloud providers offer security and technology services, such as encryption and identity and access management tools.
However, it is the company’s responsibility to implement the offer and use best practices to protect their data. The shared responsibility model helps identify which components are the responsibility of the cloud vendor and which users must safeguard.
Some organizations choose to keep workloads in place – especially those that have stringent regulatory or governance requirements.
Public Cloud Adoption and Providers
The public cloud market is led by several key players: AWS, Microsoft and Google. These providers provide their services via the internet, or through special connections, and use a basic pay-per-use approach. Each provider offers a variety of products that are oriented to different workloads and company needs.
The pay-per-use pricing structure offered by most public cloud providers is also seen by some companies as an attractive and more flexible financial model. For example, organizations take into account their public cloud services as operational or variable costs rather than capital or fixed costs. In some cases, this means the organization does not need a long review or advanced budget planning for public cloud decisions.
However, because users typically use public cloud-based services in a standalone service model, some companies find it difficult to accurately track the use of cloud services, and potentially pay more cloud resources than they actually need. Some organizations also only choose to directly supervise and manage their own local IT resources, including servers.
Estimates of the use of public cloud vary widely in different countries, but most research companies and market analysts expect continued growth in cloud adoption and revenue worldwide.