Cloud computing is a hot topic these days and while nearly every IT professional knows what it is, the rest of the world is still unsure about it. In my current job, part of my responsibilities is to explain this concept in the simplest terms especially for non-technical people and I do this by saying that cloud computing simply changes how we acquire computers or software. The following two slides are usually part of my arsenal:

I start with the above slide by talking about how, in the past, it would take weeks or months to acquire computers or software and, at the end of that acquisition stage, you still had to deal with installation and configuration.

The first slide then dissolves into this next slide. Sometimes I add animation to the arrow by making it shorter and shorter until only the dot is left. As this happens I talk about how cloud computing removes all of that time and resource consuming process and makes the acquisition of computers or software nearly instantaneous.

Of course, I follow this up with other slides that give more depth to the topic, but I've observed that these  introductory slides are the ones that puts everything into context for the audience and make them go 'aha!' or even 'wow.' Notice how sparse the slides are. And yet, from my experience, they are very effective. That's because the slides don't compete with me for attention. Rather, they emphasize the message I'm trying to deliver from the stage.