Remember versus know judgements
There is evidence suggesting that different processes are involved in remembering something versus knowing whether it is familiar. It appears that "remembering" and "knowing" represent relatively different characteristics of memory as well as reflect different ways of using memory. To remember is the conscious recollection of many vivid contextual details, such as "when" and "how" the information was learned. Remembering utilizes episodic memory and requires a deeper level of processing (e.g. undivided attention) than knowing.