File Format MXD

Definition
MXD (Map Exchange Document) is file format in which the maps created from ArcGIS software can be stored. MXD not only stores maps but also stores the symbology, layout, hyperlinks, toolbars added, etc. at the time of saving the map document. An MXD can be distributed along with the data; hence whenever the MXD is opened the symbology, layout, order of layer always remains same. Custom buttons or tools added to the MXD are also retained. The setting to show/hide ToolTips on toolbar can be saved in the MXD. MXDs can be saved to be compatible with previous versions of ArcGIS software. To figure out how to utilize MXD files within ArcGIS software, refer to the Further Reading section.

Lock Customization
A 'Lock Customization' option is also available, which makes sure that the customizations done in the MXD remain intact.

MXD Doctor
If you face any issues opening an MXD or get some error or think it's corrupted, it is worth trying MXD Doctor once to try repairing it. Make sure a backup of the MXD is taken before using this utility.

MXD Defragmenter
Sometimes the size of an MXD file can be huge and distribution can be an issue. In that case, you can opt for MXD Defragmenter which defragments the MXD and reduces its size.