There probably hasn’t been this much talk about clouds since hippies discovered LSD. Only this time, the discussion involves a cloud that can't be seen – with or without LSD - and it's generating a new kind of buzz. Here we'll take a look at cloud computing, what it has to offer and why so many people are talking about it.

Why the Buzz About Cloud Computing?

The cloud is the Internet. Yep, that old thing. What is different this time around is that the Internet is a lot further along now. The old Internet was mostly good for sending email, chatting and visiting Web pages. The current Internet has all that plus the ability to run applications. What this means is that any Internet user can use a thin client and run a program on someone else’s servers. This doesn’t sound groundbreaking, but it is. Imagine that your neighbor has a top-of-the-line computer that can run the biggest, baddest software out there, and you have a laptop that can’t even load a trial version of solitaire without getting bogged down. Cloud computing allows you to use your laptop to access the processing power of your neighbor's computer over an Internet connection. This means you can use every program on it without having to replace your laptop.

This is the basic principle behind cloud computing - except that rather than accessing you're neighbor's resources, you're tapping into a cluster of top-end hardware - and you're probably going to have to pay for what you use. That said, the idea of borrowing computing power over the Internet is just the start.

Cloud Computing’s Big Secret

Perhaps the most confusing thing about cloud computing is that you are very likely already doing it. If you have a Web-based email account through Hotmail, Gmail or Yahoo! Mail, you are a cloud computing veteran. If you have uploaded photos, watched a movie on Netflix, created a Google Doc or posted something to Facebook, you’re a cloud computing pioneer. These activities all fit the description of cloud computing because they don’t put any burden on your computer beyond running a Web browser.

Splitting up the Cloud

The cloud is actually broken into categories according to the type of service it's providing. There isn’t universal agreement on these, but the current thinking is as follows.

Software as a Service (SaaS)
Software as a service includes many of the online applications we were just talking about. Google Docs, for example, works a lot like a traditional word processing program, except it doesn’t exist on your computer. Software as a service is any program where the majority of the work is being done on another machine over the Internet. You may have to download a thin client to access some of these cloud computing applications, but many can be run through a browser. One of the primary benefits of SaaS is that it allows you to run the newest software without having the newest machine.

Platform as a Service (PaaS)
Platform as a service (PaaS) is a bit like a create-your-own-computer, except with a virtual computer taking the place of a real one. With PaaS you can select the software and services you want and customize them. The PaaS may come complete with a central interface like a traditional OS.

Infrastructure as a Service (IaaS)
Infrastructure as a service (IaaS) is actually one of the first applications to which cloud computing was applied. Infrastructure includes the basics like data storage, Web hosting, processing power, and so on. Rather than building all that infrastructure yourself – buying servers, setting them up, updating them, making sure they stay secure, and so on – you pay for infrastructure like you would a utility. The more you use, the more you pay. This allows your resources to scale up with your needs, rather than having to invest in more resources in advance or rushing to put them together in a pinch.

As you may have guessed, IaaS is more of a business aspect of cloud computing, but anyone who has ever filled a hard drive with music and photos can appreciate the beauty of storing all that data somewhere safe to free up your computer for more. (To learn more about cloud computing in business, see A Beginner's Guide to the Cloud: What It Means for Small Business.)

Everything Old Is New Again

All in all, cloud computing is not such a revolutionary idea - most of us have already been using it for years. That said, if anything about cloud computing is understated, it's its power. Google and other cloud capitalists envision a future where your device is essentially a low-cost, thin-client interface, while all your data, programs and work is stored securely and safely in the cloud. Computer broken or stolen? Pick up a new one, log in and find all your stuff waiting there. Whether we’ll give up the idea of keeping our data “safe at home” in a hard drive is an open question, but cloud computing's indisputable advantages are also winning over a lot of fans.