Your friend has no technical backgroud, yet she is curious about technology. Recently she asked you what Cloud Computing is. What would you tell her? How would you explain its concept and various models to someone with little or no technical background? Here's a suggestion. Compare Cloud Computing to everyone's favorite food, pizza!
That's exactly what HP does. In a Youtube video titled Cloud pizza, HP Norway's Technology Director, Stig Alstedt, explains Cloud Computing by comparing it with pizza. Let's see how.
Homemade Pizza = Traditional IT
Back in the old days, if you wanted pizza for dinner, you had to make your own. In that case, you buy all the ingredients, knead the dough, make the curst, chop the vegetables, and bake the pizza. You also need proper cookware. The process requires expertise, but you get exactly what you want, how you want it, when you want it. Homemade Pizza is equal to building your own IT infrastcture with your own resources.
Frozen Pizza = Private Cloud
Nowadays supermarkets offer customers a variety of frozen pizzas, Pizza manufacturers do almost all the work. You just select one from the frozen pizza aisle, bring it home, and bake it in your own oven. It's convenient, but the flavors and prices are fixed. Frozen Pizza is similar to Priviate Cloud.
Delivered Pizza = Managed Cloud
Delivered pizza is a bit more convenient than frozen pizza. You order what you want and how you want, then the piza is delivered to your doorsetp. No baking is necessary. However, menu items are limited and you still need your own dishes. Deliverd Pizza is close to Managed CLoud.
Restaurant Pizza = Public Cloud
Restaurant pizza requires the least expertise because the restauarnt provides you with everything. You simply show up, order, eat and pay. You get one invoice at the end of your meal. However, other customers alson dine in, so the service can be slow when the place is crowded. Furthermore, everyone orders from the same menu. It means there is not much room for individual customization. Restaurant Pizza is comparable to Public Cloud, except that Public Cloud is often the most inexpensive option while restaurant pizza is not.
Your Own Topping = Hybrid Cloud
Many pizza delivery places and restaurants offer an option to choose your own topping. Hybrid Cloud is like choosing your own toppings to make your favorite pizza.