There are three cloud computing models. You can lease infrastructure (Infrastructure-as-a-Service or IaaS), a platform (Platform-as-a-service or PaaS) or a range of software applications (Software-as-a-Service of SaaS) in the cloud.

Infrastructure-as-a-Service is the base layer of cloud computing. This comprises everything you would normally purchase as physical hardware: servers, hard drives for storage, firewalls, network equipment and much more. However, instead of buying them and accommodating them in a server room, you just lease the virtual equivalent from a specialist company which hosts these services.

This is the layer that connects your infrastructure and your software. Thanks to Platform-as-a-Service, anyone who wants to design and build software can easily do his or her own thing: it comprises tools and programs which you can use to design and build applications easily, and then offer them as SaaS (see below). And PaaS also includes the same virtual infrastructure as IaaS.

Software-as-a-Service is the cloud computing model that most of us know best, and probably even use on a daily basis. It consists of a range of services that we use via our browser: e-mail, online word processing and accounting programs, CRMs and so on. You don’t buy the program, you just subscribe to it. All the hardware runs in the cloud, on a host’s servers. Data is also stored there: protection is therefore excellent. You don't have to install anything or update the software, either: it’s all done automatically. In short, just log in and get down to work!

There are two ways to get access to the three models in the cloud explained above. When we say ‘in the cloud’, we may be talking about two different things: ‘public cloud’ or ‘private cloud’ - in other words, a public cloud environment or a private cloud environment. What’s the difference?

Well, most of the things we use ‘in the cloud’ are in what’s known as the public cloud: e-mail programs, data backup (and your holiday snaps) etc. You can compare the public cloud with a gigantic apartment building where you rent a little studio apartment, have your meals in a communal restaurant and work out in the basement gym. You don't have to take responsibility for maintaining the building, the caretaker does that. And all these services are simply included in the price you pay.

A private cloud, on the other hand, is like renting a whole house. You can split it up depending on your own wants and needs, but you also have to look after it a bit more. And you’re entirely responsible for the maintenance; if a domestic appliance ever needs replacing, you have to take care of it yourself. No to mention the security. However, the information you store there is always kept separate from your neighbours’.

You can easily run a business with servers, storage space or software application that exist solely in the public cloud, in other words are not actually present in your office. As mentioned, you lease everything from a third party: a host. With a private cloud, you yourself install the infrastructure for a group of users - in most cases, your employees. They then use the services that you’ve organised for them, and log into your network directly, with or without a VPN connection.

Both options have pros and cons, so the answer to the above question is: it depends. On the kind of business you are, naturally. On the number of employees you have under your roof. On your ambitions, as well.

You have more autonomy with a private cloud: you can therefore also take care of the security yourself - but in that case, you’ll have to invest a substantial amount of time and energy in it.  You can also manage your own data, but the same thing applies: you have to spend a lot of trouble and money. One option may be to outsource the hosting, set-up and management of your own private cloud environment. You then have the benefits of both the public and private cloud, though you generally need a certain scale to be able to do it cost-efficiently.

What are the benefits of cloud computing? Read our blog here

Curious to find out the best cloud option for your business? Read here how Dstny can set up your cloud infrastructure