The term Collective Unconscious is an intuitive lesson by Dr Carl Jung, a critical issue in our life to understand the psyche. It is mostly misunderstood by many people, even his faithful Jungian fans, in the way of some sects, or he might talk about some elite groups of exceptional class!
It has nothing to do with any group of people generally but directly with a single person individually. It is a matter of Persona, individual history, and past heritage (Archetype), which we might have totally forgotten, but it has remained in our unconsciousness.

In other words, in the description from the book in German: ( Archetypen) published by dtv. which I chose and translated:
With the model of “archetypes”, C. G. Jung created one of the Keystones of his analytical psychology. Taken from ancient tradition, the term “archetype” refers to the archetypes of human imagination located in the collective unconscious. As a part of the psyche, the archetype is a hypothetical unit of the collective unconscious and manifests itself in images that are not a reflection of biological drives but rather autonomous and not immediately recognizable to humans. Above all, the most elementary human experiences such as birth, marriage, motherhood, separation and death have an archetypal anchoring in the human soul; they have produced similar images at all times and in all cultures and can be regarded as collective human experience. Their range of variation is just as great as their wealth of relationships; to perceive them, to analyze their appearance in images means to perceive the archetypal dimensions in the life of every human being and to use them for the development of the soul. From the numerous writings of C. G. Jung on the archetype, this volume brings together those that most clearly express his ideas on it.

Dr Jung explains:

Probably none of my terms has encountered as much misunderstanding as the idea of the collective unconscious. In the following, I will try to give 1. a definition of the term, 2. a presentation of its importance for psychology, 3. an explanation of the proof method and 4. a few examples.

Definition

The collective unconscious is a part of the psyche which can be negatively distinguished from a personal unconscious in that it does not owe its existence to personal experience and is, therefore, not a personal acquisition. While the personal unconscious consists essentially of content that was conscious at one time but has vanished from consciousness, either being forgotten or repressed, the contents of the collective unconscious have never been in consciousness and thus have never been individually acquired but owe it Existence exclusively of heredity.

The notion of the archetype, which is an indispensable correlate to the idea of the collective unconscious, indicates the presence in the psyche of specific ubiquitous or pervasive forms. Mythological research calls them “motives”; in the psychology of primitives, they correspond to Levy-Bruhl’s concept of “representations collectives”, and in the field of comparative religious studies, they were defined by Hubert and Mauss as “categories of imagination”. A long time ago, Adolf Bastian called them “elementary” or “primal thoughts”. From these references, it should be clear enough that my idea of the archetype – literally a pre-existing form – is not exclusively my concept but also recognized and named in other areas of knowledge.

So my thesis is as follows: In contrast to the personal nature of the conscious psyche, there is a second psychic system, of a collective, non-personal character, alongside our consciousness, which in turn is thoroughly personal in nature and which we—even if we consider the personal unconscious as Add appendages – believe to be the only psyche that can be experienced. The collective unconscious does not develop individually but is inherited. It consists of pre-existing forms: the archetypes that can only become conscious secondarily and entice the content of consciousness into a definite form.

To understand it better, I split this into some parts, which may be easier to catch the points. 😉🤗

The image on the top: Surrealism AI Art Spirituality Dark Weird Collective Consciousness Absurdism Illusion Imagination (Ethereal Luna, Pinterest)

Source:

On “The concept” of the collective unconscious (1936): Lecture 1936 in the Abernethian Society at St Bartholomew’s Hospital, London, under the title “The Concept of the Collective Unconscious < published in the journal of that hospital, XLIV, London 1936/37, p .46-49 and 64-66. The first edition of the German translation in Collected Works (CW), Volume 9/1, pp. 55-66.