The mechanical browser shows the hierarchical organization of parts and assemblies in a mechanical structure enabled drawing.
When you start AutoCAD Mechanical toolset for the first time, the mechanical browser may not display automatically. You must switch to the structure workspace or use the AMBROWSER command to turn it on. Once it is turned on, it remains displayed (even if you close AutoCAD Mechanical toolset and restart it) until you explicitly close it.
In addition to displaying the structure of a drawing, the mechanical browser provides context sensitive right-click menus. This enables you to quickly find the tools that apply to the type of object you select in the mechanical browser. It also supports drag-drop editing, which enables you to reorganize the structure of the drawing visually.