A basemap is the undermost layer on the map. Everything that is mapped is visualized on top of the basemap.
The basemap control is located in the top right of the map screen:
Clicking it will expand the basemap control, revealing all the basemap selections, there are several to choose from:
Selecting a radio button next to one of the options will change the basemap to the selected one:
Need more clarification?
Contact support using the chat widget and we can help you out!