A family of Microsoft relational database management systems designed for ease of use.
The basics of shapes like this are multiple shapes within a group as well as multiple geometry sections, making these sections visible/invisible via the Actions section of the shapesheet. Put a shape on a page and use the Drawing Explorer window to look at the way the shapes expand within a group, then use the Shapesheet editor to look at the various cells within the shape and how they interact.
You will need to run Visio in Developer mode (File -> Options)
Hope that helps.