The Map Areas tab is available by default when you open a mission. There is always a live mission map at the top of the list. You also have access to any downloadable maps that have been created for that mission, including existing downloadable map areas.
The live mission map is accessible to all mission members and is always the main map used for any mission. Most of the work done in a mission appears on the live map, and you can access all of the tools used during a mission from the map.
When you access the mission map, your status changes from inactive to active.
Offline maps
Downloadable maps are created to support offline use of ArcGIS Mission Responder. These are mission-critical map areas that are created in preparation for a mission in a disconnected environment. They contain a small section of the mission map that functions similar to the live map, although tools and map functionality are limited by the lack of connection.