These pages are essentially based upon the Jmol application, and its JSmol variant, developped for websites.

You can play on this first page by searching molecules on the PubChem or RSCB servers.

By clicking on the appropriate parts of the scheme and rotating the structures in 3D, you can explore the geometry of a molecule.
Mouse gestures: use the scroll wheel to enlarge and shrink the models; shift + double-click on any atom and drag to translate along (x,y)
right clicking the mouse (Control-click MacOS) over the JSmol screen will give additional options and features.

To navigate your way to the required page, simply use the side-bar on the left.
According to the page, additional buttons are available and perform the labelled features.