Among the new features in Build 410 is the revamped ArcGIS Explorer Resource Center. The Resource Center now includes a Contents tab that provides easy access to both maps and layers.

What's the difference? Well choosing a map will replace your existing map; in other words it's like opening a new document in ArcMap or Word. Choosing a layer will just add the chosen layer to your existing map, just like adding a layer to ArcMap. Just click on the thumbnail or name. Click description to view more information about each map or layer.

Previously, to add a layer you needed to connect directly to the ArcGIS Online servers using a provided URL, user name, and password. Based on your feedback, we've redesigned things so that adding layers is easier than ever before.