The most popular cloud services for individuals and small businesses are Apple's iCloud, Microsoft's SkyDrive, Google Drive, Amazon S3 and Dropbox. In one sense, they are much of a muchness as they all do pretty much the same thing, with the amount of storage space and how much (if anything) you have to pay for it. All of these services are Public Clouds; that is, they are available to members of the public and are operated by commerical companies looking for customers amongst the general public. There are numerous advantages in using a public cloud. For a start, they are provided by enormous organisations that have the funding and expertise to provide a safe, reliable service that is always available. Also, there are considerable volumes of scale: with tens of millions of customers, they are able to provide a low cost service (as mentioned above, it can even be free).
But, there are some disadvantages with public clouds. First, there is the question of trust: just how safe is your data? This doesn't just mean safe from prying eyes (hackers), it also means safe from the provider of the service. Some cloud operators, for instance Microsoft and Google, state in their terms and conditions that they reserve the right to look at and use your data. Now, you might expect that they need to take reasonable precautions to guard against the storage of material that is clearly illegal (terrorist manuals, pirated software and movies, certain types of pornography), and to provide controlled access to the security services under proper safeguards. But do you really want them trawling through your accounts or customer database or other documents to build up a profile of you and your business? Do you want one of your photographs subsequently appearing in an advertisement somewhere without your knowledge? Or to be bombarded with advertisements based on what they have determined to be your interests? All of these eventualities are catered for in the T&C of some of the big players.
Secondly, what if the cloud provider changes the rules? That is, you might be very happy with the way their system operates in terms of pricing, performance, device availability and user interface. But one day you might find that they have changed things, that the system operates differently and that certain facilities have been withdrawn or your operating system is no longer supported (example: Apple's iCloud used to work with Windows XP. It no longer does so). It is unlikely that any of the big names will suddenly cease trading, but what if one of them decides that it no longer wants to be in the cloud business - what happens to your data then?
Thirdly, although most cloud providers give some free storage, it may not be enough for you and the cost of additional space may be more than you are prepared to pay. For instance, Apple provide 5GB of storage for free (actually enough for a lot of people) but if you need more - say 50GB - then it is £70 a year.
The answer to all of these questions is: a Private Cloud. This is one that you run yourself, one that is totally under your control (Your cloud. Your rules). As the data stays with you, you can feel secure that it is safe from prying eyes. And you can use it as much as you want, without any additional charges. Suddenly need 100GB rather than 5GB? No problem.
Now, you might think that setting up a private cloud is something well beyond the capabilities of the average person or small business and, a few years ago, this was certainly the case. However, most modern NAS (Networked Attached Storage) boxes have the capability built-in. It's simply a matter of ticking a few boxes and answering one or two questions and you are up and running. Even consumer grade NAS boxes - the ones that sell for little more than £100 in the likes of PC World, Comet and Maplin have this capability. On prosumer (professional consumer) or small business NAS from the likes of Synology and QNAP, these private cloud facilities are every bit as sophisticated as what you get from Microsoft and Google et al, but without the limitations of price and capacity.
Are there any pitfalls to be wary of? Yes. Because your NAS is connected to the internet then potentially it is susceptible to the activities of hackers, although realistically it is not much different than having, say, your normal computer connected and your probably don't worry too much about that. However, you should have a router with a decent firewall, avail yourself of any security features offered by the NAS box, plus use proper passwords on your accounts and change them from time to time. We would normally recommend prosumer equipment, for example Billion routers and Synology NAS