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. 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 cloud. In contrast, private cloud involves cloud-based services that are hosted within an organization’s own private servers.
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 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 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 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 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 cloud as one element of a multi-faceted IT plan. This way, they can access the benefits of cloud while also maintaining the different benefits that come with on-premises architecture and private cloud options.