When working in a assembly you can select a assembly (even through there is only one assembly) and you can make parts in your assembly lightweight. How do these work???
I don't understand your question/concern. Remember, there's a part file that is called the Assembly which contains only the structure of the Assembly and things like constraints and attributes. When you are working in the Assembly Navigator, Irrespective of whether you're working on context or not, the entire assembly is being displayed and the Components are listed. So if you wish to select the entire Assembly, INCLUDING it's Components, this is how you do that, by using the 'Select Assembly' function. Just selecting the Part file that holds the Assembly will ONLY select that part file but NOT it's Components. This 'Select Assembly' function is just that, a way of selecting ALL the parts that make-up the Assembly at once.
That being said, why are you asking these questions? What is it about this 'Select Assembly' function that is causing you concern? It's purpose should become pretty obvious if you simply try using it.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA Siemens PLM: UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.