|File Type||ArcGIS Map Document|
|File Format||Proprietary (ESRI)|
|Popularity||★ ★ ★ ★ ☆ Common|
Map file format used by ESRI mapping software, such as ArcMap; saved in a compound format that includes the map description, layout, and embedded objects saved in the map; organized into units called storages and streams.
Important: MXD map files may grow in size after being saved multiple times because they can become fragmented. Saving a fragmented map document as a new document may reduce its file size.