The Document View tab displays a list of all the documents the assembly is built upon, that is the main assembly file and all its external components (X-Refs).

The information listed for each item includes:

Component the name assigned to the component
Qty the number of occurrences in the assembly
Mod. the Modify flag, meaning changed but not yet saved document
Doc. Name the Document Name assigned to the model
Doc. Description the Document Description assigned to the model
Lock User the name of the users locking the file
L.C. the Local Copy flag, meaning document in local copy
R.O. the Read-Only flag, meaning read-only document
Children the number of component children — that is the first level components — that the single document includes
File the pathname of the relevant file

In the lists displayed in the Document View tab and in the Document View tab, each item is associated with two icons. Click here for more information.

Take a look at the video list  e-Learning on Assemblies and Mating