Anyone just starting out with the cloud is going to need answers to some basic questions.
The first, of course, is what exactly is the cloud? Put simply, the cloud is a collection of purpose built servers. These servers could perform one or more services (storage, compute, database, email, web, etc.) and could exist anywhere as long as they’re accessible to whomever needs to use them.
The next important question to ask is whether the servers are in a private cloud or a public cloud. This distinction is often tied to where the servers are located, but more precisely, it reflects who uses the servers and how they use them.
What is Private Cloud?
If the servers are owned by and dedicated to only one tenant (user) or group of related tenants, they are in a private cloud. The private cloud is typically on-site (or on-prem or on-premises in IT lingo), but it could be off-site, as well. The owner is responsible for the management and maintenance of the servers and for planning for future capacity and performance to meet the needs of its users. This planning usually involves long lead times to add additional hardware and services (electricity, broadband, cooling, etc.) to meet the future demand.
What is Public Cloud?
In a public cloud, the servers are shared between multiple unrelated tenants (users). A public cloud is off-site (or off-prem or off-premises). Public clouds are typically owned by a vendor who sells access to servers that are co-located with many servers providing services to many users. Users contract with the vendor for the services they need. The user isn’t responsible for capital expenses, data is backed up regularly, and customers only have to pay for the resources they use. If their needs change, they can add or remove capacity very quickly and easily by requesting changes from the vendor who reserves additional resources to meet demand from its clients.
Differences: Private Cloud vs Public Cloud
|Private Cloud||Public Cloud|
|Single client||Multiple clients|
|On-premises or off-premises||Off-premises|
|Capital cost to set up and maintain||No capital cost|
|High IT overhead||Low IT overhead|
|Fully customizable||Limited customizations|
|Fully private network||Shared network|
|Possible under utilization||Scalable with demand|
Which Cloud is Right For You?
If you’re a big company or organization with special computing needs, you know whether you need to keep your data in a private data center. For businesses in certain industries, for example, government or medical, the decision to host in a private or public cloud will be determined by regulation. These requirements could mandate the use of a private cloud, but there are more and more specialized off-premises clouds with the necessary security and management to support regulated industries.
The public cloud is the cloud of choice for those whose needs don’t yet include building a dedicated data center, or who like the flexibility, scalability, and cost of public cloud offerings. If the organization has a global reach, it also provides an easy way to connect with customers in diverse locations with minimal effort.
The growing number of vendors and variety of public cloud services indicate that the trend is definitely in favor of using the public cloud when possible. Even big customers are increasingly using the public cloud due to its undeniable advantages in rapid scaling, flexibility, and cost savings.
Enter Multi Cloud and Hybrid Cloud
For some, a combination of clouds could provide the best solution. Using multiple public cloud vendors (multi cloud) for independent tasks and duties can provide redundancy and cost savings. The data centers and infrastructure can be spread out geographically to decrease the risk of service loss or disaster, and it makes sense financially to store the second or third copy of data with an additional vendor that offers a good and reliable service at a lower cost.
Hybrid cloud refers to the presence of multiple deployment types (public or private) with some form of integration or orchestration between them. The hybrid cloud differs from multi cloud in that in the hybrid cloud the components work together while in the multi cloud they remain separate. An organization might choose the hybrid cloud to have the ability to rapidly expand its storage or computing when necessary for planned or unplanned spikes in demand, such as occur during holiday seasons for a retailer, or during a service outage at the primary data center. We wrote about the hybrid cloud in a previous post, Confused About the Hybrid Cloud? You’re Not Alone.
Choose the Best Cloud Model For Your Needs
For most businesses and organizations, the important factors in selecting a cloud will be cost, accessibility, reliability, and scalability. Whether the private or public cloud, or some combination, offers the best solution for your needs will depend on your type of business, regulations, budget, and future plans. The good news is that there are a wide variety of choices to meet just about any use case or budget.