What is the difference between public, private and hybrid cloud? You come across the terms all the time, but still the difference between all these types of cloud is not entirely clear. This is normal, because it’s not so sharply delineated in actual practice either. But we will set out an overview below.
The public cloud is the one which everyone actually uses. Privately, we have been active in this public cloud for much longer, even though we don't usually call it that. Who doesn't use webmail or online storage for photos? So this is what the public cloud is: an easily available way to store and use files, and to work with all kinds of software applications. Now we are also making full professional use of it – just think of Microsoft Azure and Amazon Web Services.
The public cloud is so-called because the users share the underlying infrastructure. Access to your data is password-protected, but you are not the owner of the hardware or software. What's more, you don't even know where the servers are located.
The benefits of the public cloud
Above all, the public cloud is very user-friendly and extremely scalable. Since you don’t own the IT, you don’t have to worry about it. In other words, no investments in servers for growth, no maintenance or updates. You only pay for what you actually use, for example per user per month, so you have perfect control over costs and they are very predictable. Need more capacity: no problem. The possibilities of the public cloud can be expanded very easily and flexibly.
In fact, the public cloud is like water from a tap: you pay a subscription and then you use the amount needed at any given time. The providers of public cloud services are large, reliable companies that maintain their data centres in tip-top condition and provide all the necessary security and backup. In effect, this gives you access to an IT infrastructure that can guarantee higher availability than you could ever achieve on your own.
The private cloud is very different from the public cloud. As the name suggests, with a private cloud you don’t have to share any hardware or software with other organisations. So a private cloud is used by a single organisation.
Sometimes there is still some discussion about the possible configurations of a private cloud. In general, we can say that the private cloud infrastructure can run in an organisation's own data centre, but it can also be hosted by an external cloud service provider. In this case too, the infrastructure is reserved for that one organisation. The service provider can then more easily manage the maintenance and it usually also has a better equipped data centre. So there are economies of scale compared to having your own local data centre.
The benefits of the private cloud
The private cloud is more private, which is also why organisations prefer to store certain information there rather than in a public cloud. This is often the case, for example, with banks, governments or other organisations that work with privacy-sensitive information over which they want to keep as much control as possible.
Another advantage: because you are the owner of the IT resources in a private cloud, you can flexibly adapt the environment according to exactly what your organisation needs. It is not a one-size-fits-all, but it is customised. And that scalability is also a good thing: with a cloud infrastructure that is hosted in the data centre of an external cloud provider, scalability is in any case a lot higher than with an IT infrastructure that runs locally (‘on-premises’).
The hybrid cloud
The hybrid cloud is – again very logically – a combination of private cloud and public cloud. More and more organisations are working in this way. For example, they use cloud software for their e-mail, but for other business-critical or very heavy applications they opt for the private cloud.
It is even perfectly possible to use different private clouds, multiple public clouds and on-premises IT infrastructure together. This is often a transition phase because, for example, there was a recent investment in a locally running server.
The benefits of the hybrid cloud
The hybrid cloud is, above all, tailor-made: the organisation decides which type of cloud should be used for which applications or data. An application runs in a particular cloud environment according to the desired security, compliance, continuity, privacy, flexibility, speed, and of course, the budget. Behind the scenes, at least, it is different every time. But it shouldn't make any difference to the end user, who just has to be able to work efficiently.
A hybrid cloud must be manageable as a single virtual entity. This is usually done by external experts who provide managed hybrid cloud services. This is the only way to really get all the benefits out of the combined configuration. For example, if the on-premises infrastructure does not meet the requirements, say due to a major marketing campaign, it should be possible to use the capacity of the public cloud flexibly and securely.
A big advantage of the hybrid cloud is that it offers organisations of all sizes access to all kinds of innovative technologies that consume capacity, such as artificial intelligence or the Internet of Things. Hybrid cloud also proves ideal for combining with Edge Computing and SD-WAN, software-defined networking in which computing power partly shifts to connected devices or 'smart devices' in the network.