You know LEGO bricks—the multi-colored building blocks you can use to build cool things like a Star Wars™ Star Destroyer™, or an airplanes, or whatever you can dream up? A really simple way to make building whatever you can think of easier is to sort all those pieces into different groups. Maybe sort them by color, by size, and by shape. Then keep all those sorted pieces in separate boxes where they are ready for you to play with right away.
Well, in IT, those cool toys you build are called applications. And all those different pieces you build those applications out of are kept in boxes IT calls containers. The container doesn’t hold the whole toy, but some of the pieces you need to build that toy. That way, no matter what you want to build, or when you want to play with it, you can find it and play with it right away. You just grab the right set of containers, snap things together, and play!