For all the talk about cloud, it might come as a surprise to many in the industry that "cloud" is not a well-understood term. It's often perceived as "just a buzzword" or something without a lot of substance. While the term can be abused, it's actually an important concept and it's certainly not just a passing fad. In talking to people following the Apache CloudStack graduation, and meeting with the local Linux User Group (LUG), it dawned on me that cloud still bears some explanation. Let's take a look the standard definition, some types of clouds, and why it matters.