As cloud computing becomes more and more pervasive, it’s worth pausing to take stock.One certainty is that the number and variety of cloud options continues to grow, with everything from cloud printing to big data processing with Hadoop now a possibility.Choice is good of course. But the most important question, as always, is what should businesses be seeking?Here are some thoughts on options and trends in the cloud and what they mean for business:Public cloudFrom cloud applications to virtual servers, the number of companies offering public cloud services almost seems to follow Moore’s law (doubling every two years).Public clouds – like Amazon’s – are open to anyone, with access via the internet. For business, their biggest benefit is scale. The more users they gather, the better the economy of their shared resources.But more users can also mean less flexibility. Businesses can come unstuck wherever their needs stretch beyond what the public cloud provider has considered and supports, and trouble can manifest in various customisation, migration and data issues.That isn’t to say that the public cloud can’t play a role – only that, from the point of view of the complete range of a business’s needs (and concerns like data sovereignty), its uses remain limited.Community cloudsCommunity clouds are rarer than their public counterparts. Generally open to business groups who share similar needs and concerns, they can be useful if your business has needs that fall under their umbrella.A good recent example is the New York Stock Exchange’s Capital Markets Community Platform – a cloud hosting service that offers financial services companies the chance to run their trading platforms in close proximity to the NYSE’s systems.As a variation on the public cloud model, however, businesses face the same challenges, and their use is usually best limited to specific purposes.Hybrid cloudsHybrid clouds aim to tie public, community and private clouds together, creating an infrastructure in which businesses adopt multiple services from multiple providers.An attempt to get the best of all worlds, their advantage is their flexibility. And when challenges around integration and security are met, they can create a powerful platform.But their greatest strength can also be a weakness, with multiple services meaning multiple points of responsibility and management strain.Private cloudsPrivate clouds are those hosted for the exclusive use of a single business. While they don’t necessarily achieve the same economies as public services, they have no less ability to scale.Most importantly, they offer full control over data and processes, and more control means everything from better security to customisation and confidence that business requirements can be met. Not to mention clear lines of responsibility.For these reasons, the private cloud remains the number one choice for business needs.Indeed, according to IDC research, almost 7 in every 10 businesses either have or will be implementing private cloud solutions in 2012.Stephen Sims is Brennan IT’s General Manager – Sales and Marketing.