Offline maps allow you to view, collect, and update features when you are disconnected from the Internet. Once you are reconnected, you can synchronize your map, send any updates you have, and get map updates from other users.
To take a map offline, all the layers, including the basemap, need to be enabled for offline use. You can enable map layers for offline use from cached map services with Export tiles enabled (from ArcGIS 10.2.2 for Server or later), feature services (from ArcGIS 10.2.2 for Server or later), hosted feature layers, and hosted tile layers. If your map supports offline use, taking it offline is automatically enabled. If you don’t want your map to be taken offline, you can edit its item properties and disable offline mode.