Which file format is commonly used for publishing symbolized mapping layers in ArcGIS?

The Map Package (.mpk) file format is specifically designed for packaging and sharing map documents and their associated data, including symbolized mapping layers. When you create a Map Package, it includes not only the map itself but also all the elements that pertain to it such as layers, symbology, and connections to data sources. This ensures that when someone else receives the Map Package, they can open it in ArcGIS and see the map exactly as it was intended by the person who published it, along with all the necessary data to replicate that visualization.

This capability to encapsulate the map's configuration and associated files makes the Map Package a preferred format for distributing and sharing maps that need to retain their intended appearance with all symbolizations intact. Thus, it serves a distinct role in mapping workflows within ArcGIS that is not fully matched by the other options.