In obsolete|lang=en terms the difference between memory and collection
is that
memory is (obsolete) a memorial while
collection is (obsolete) the act of inferring or concluding from premises or observed facts; also, that which is inferred.
As nouns the difference between memory and collection
is that
memory is (uncountable) the ability of an organism to record information about things or events with the facility of recalling them later at will while
collection is a set of items or amount of material procured or gathered together.