Record ownership - inheritance of sharings

Hi,

I have a question regarding relationships?

What is the difference between assign and reparent?

If I define the owner for an account or contact and setup n:1 relationships to my custom entities for assign "cascade all" will then only the owner be updated, in case it is changed in the account or contact. Or will this also consider all sharings for that record?

Or is assign used for owner and reparent for sharings?

thx Thomas