This is the first card of the Home stack. It is a visual directory for HyperCard. It shows a picture for each stack that comes with HyperCard. Clicking one of the pictures will take you to the stack.
The stacks you see are simple ones provided as examples of what you can do with HyperCard. When you get or create a new stack, you can add a picture and a button to take you to the new stack.
To learn more about drawing pictures and creating buttons, click on this text field to hide it, and then click on the picture for "Intro".