Jung defines his concept of the collective unconscious:
Probably none of my empirical concepts has met with so much misunderstanding as the idea of the collective unconscious….
The collective unconscious is part of the psyche which can be negatively distinguished from a personal unconscious by the fact that it does not, like the latter, owe its existence to personal experience and consequently is not a personal acquisition.
While the personal unconscious is made up essentially of contents which have at one time been conscious but which have disappeared from consciousness through having been forgotten or repressed, the contents of the collective unconscious have never been individually acquired, but owe their existence exclusively to heredity.
I have chosen the term ‘collective’ since this part of the unconscious is not individual, but universal.
And unlike the personal soul its contents and modes of behavior are relatively the same everywhere and in all individuals.
It is, in other words, identical in all men and thus constitutes a common psychic substrate of a super personal nature which is present in every one of us. ~Carl Jung, Archetypes of the Collective Unconscious