The Zoom tools are unique to digital maps. They are very much like using an actual magnifying glass, as the icons imply. The tool with the little plus sign lets you 'zoom in', while the one with the little minus sign lets you 'zoom out'. There are a couple of ways to use these tools. First, select one of them, go somewhere on the map and press the left mouse button. If it is the Zoom In tool the map zooms in. The center of the new map is wherever on the map you clicked the mouse button. The Zoom Out tool zooms out the same way. Second, you can zoom in more precisely by pressing the mouse button somewhere on the map, holding it down, and dragging a box. When you let go of the mouse button the new map extent will be the area defined by the box. When zooming out, the area defined by the box becomes the new map extent. On a Geographic Data Viewer map, a maximum and minimum scale may be set. A maximum scale is set so you can't zoom in further than the data is designed to be used at. A minimum scale is so that people don't zoom out beyond where there is information.

Zooming in also increases the scale of the map. Scale is a ratio. 1:10 means that every unit on the map represents ten units of the real world. Which means the map is one tenth of the size of the real world. As well, some layers or labels for layers may only appear at certain scales. This is to improve the speed of the maps and to prevent them from getting cluttered at different scales.

There are a few other handy buttons that will make life easier.