When you removed duplicates from a table, which record does it keep?

I have a dimension table and sometimes a duplicate creeps in so I have a de-dup step. However, is it keeping the top-most record? Or bottom? Or is there other logic involved?

I ask because, if I filter date descending so I have the most recent records at the top, then de-dupe, can I safely tell my customers they are seeing the most recent version of that record?