Cloud computing wasn't all that popular when it was first introduced. How things have changed since then. Not only is the cloud extremely popular, but it is also now the norm for business applications and services. So much so that the big choice today is between public and private cloud environments. Is one better than the other? As with most things technology, it’s not that straightforward. There are cases that justify the time, effort, and expense of maintaining a private cloud. There are other cases in which public clouds are the better option. Determining the right option in any scenario is a matter of figuring out what an organisation's needs are. The Cloud Is Not a Mainframe Some of the confusion surrounding cloud computing relates to a misunderstanding of what it is. First off, the cloud is not a mainframe. It is a means of providing hardware, data storage, networking, and software services remotely. One could consider cloud computing a direct descendent of the old mainframe model, but it is so much more than that. With the cloud, companies do not have to host any of their own hardware or software. They don't have to maintain applications and databases on servers in their own offices. Everything in the cloud can be accessed from anywhere in the world using a mobile device or computer. The cloud provides everything you need with global access, backed up by cutting-edge security. The Difference Between Public and Private A public cloud environment is one that is hosted in a data centre on server space that may share resources with other clouds. A public cloud is not restricted by an exclusive firewall to prevent outside access. So while there are security measures in place to protect public cloud data, the actual server space on which that exists is not walled off. A private cloud is just the opposite. It provides a specific set of hardware and software services to a specific clientele, all protected behind an exclusive firewall and with resource sharing. More often than not, private clouds are hosted on private networks. It is possible to combine both private and public clouds in a hybrid scenario. Those services that are not mission-critical or extra sensitive to security can be in the public space while everything else is hosted in the private cloud. Choosing the Right Option Cloud environments offer services in one of three general categories: Software-as-a-service (SaaS) Infrastructure-as-a-service (IaaS) Platform-as-a-service (PaaS). Both SaaS and IaaS can be hosted in a private cloud scenario, but they are found more often in public clouds. Microsoft Office 365 is a good example. It is a SaaS product accessible to customers via a public cloud. Choosing Private over Public So, are there any reasons for choosing a private cloud instead? Absolutely. A private cloud is the better option if data and infrastructure require the best possible security at multiple levels. When you go private, you are not trusting third parties to manage the environment. Take third parties out of the equation and security automatically increases. Owning and operating your own data centre is another reason for developing a private cloud. As long as you are putting the time, money, and effort into data centre operations, you might just as well host your own cloud. There is no point in paying a third-party to do something your company is already set up to do. The desire for absolute control and customisation is yet another reason that drives some companies to make their clouds private. When you manage everything in-house, all the decisions are yours. You control everything from the hardware deployed to your strategies for compliance. Choosing Public Over Private Running a private cloud has advantages, but it is no walk in the park. Companies truly have to be committed to pull it off. That commitment includes a commitment to resources, without which it is better to go with a public cloud environment instead. The primary benefit of public clouds is that they are managed by third parties. You pay for the hardware and software you need. The provider handles everything from maintenance to security updates. And when hardware needs to be replaced – and it always does, eventually – it is the provider's problem, not yours. Public clouds are not without their downsides. They almost always share resources, so there can be some speed and accessibility issues if a provider doesn't stay on top of things. Furthermore, you might end up paying for things you don't need in a public cloud environment. You also do not have absolute control over infrastructure and security. Both public and private clouds serve a valuable purpose. Neither is necessarily better or worse than the other. It is all about options, and the one that best meets the needs of your organisation is the best choice for you.