 Each of these different categories contains a couple of different elements. You've got an adaptive card object. This is the root object that describes the adaptive card itself, including the element markup, its actions, how it should be spoken, and the schema version that's required to render it. And then many cards also have a set of actions that a user may take on them. That text can contain markdown that'll get rendered out for you. Now, card elements include the different controls that can be added to the body property of the card. And these include elements such as a text block. You have an image control. For example, video would be video slash mp4. You've also got things like a rich text block.