The marker pins refer to the sections as used in the Scottish Mountaineering Club manuals and also on this web site. Click on a marker pin and it will reveal the name of the section which can be use to locate the Munros, Corbetts and some Grahams (those that I have climbed) within that area.
You can also use the zoom and pan bar on the top left hand corner of the map. The hybrid on the top right hand corner will give you the topography of the area.