Linked data Platform Containers / Collections Confusion

Dear all,

Forgive me for asking similar questions about the linked data platform on
similar lists. It is not clear to me what things in linked data platform
containers should look like. I have many thoughts occupying my mind, but
here is something to begin with:

"My impression is that things in a linked data platform container must have
a particular pattern and that things in a linked data platform collection
do not."

Is this true?

I cannot just pick a set of random triples from the giant global graph and
call it good?

-Brent Shambaugh