City Navigator North America NT 2017.10 --> The latest version of the NA road map for nuvi, zumo, etc.
Garmin City Navigator North America NT 2015.40 --> Old version of the NA road map, forget about it.
City Navigator North America 2009 MapSource (NON-NT) --> "ancient" version of the NA road map ("Mapsource" means this map is for PC installation, ".img" or "image" is the Garmin device version of the map).
Approach CourseView Americas CourseView is the name of a series of Golf Courses maps around the world and Approach is the name of the Garmin device that uses them when you play golf.
OSM based North America Maps for Garmin fenix --> OpenStreetMap.org based map, with very limited set of map features, black and white, especially designed (...shrank version) for the wrist watch Fenix and very small in size

BlueCharts are Garmin's marine maps (charts) for use with Garmin Marine GPS plotters and most On The Trail devices. Nuvis and Zumos can't show the map correctly and with the right colors (ie green depth contours). 90% of the info these maps contain can't be shown on Garmin On The Road devices.
Your Zumo can read road maps like City Navigator North America NT XX.XXX and various Topo maps