Throughout school and college, one of the subjects I loved much was Psychology. Abnormal, Child Psychology, and other parts of fascinate me. Why? I like learning how the brain works.

Consciousness is a type of mental state, a way of perceiving, particularly the perception of a relationship between self and other. It has been described as a point of view, an I, or what Thomas Nagel called the existence of “something that it is like” to be something.

Consciousness may involve thoughts, sensations, perceptions, moods, emotions, dreams, and self-awareness. It has been defined from a biological and causal perspective as the act of autonomously modulating attentional and computational effort, usually with the goal of obtaining, retaining, or maximizing specific parameters, such as food, a safe environment, family, or mates.

The issue of what consciousness is, and to what extent and in what sense it exists, is the subject of much research in philosophy of mind, psychology, neuroscience,cognitive science, and artificial intelligence. Issues of practical concern include how the presence of consciousness can be assessed in severely ill individuals; how non-human consciousness can be measured; at what point in fetal development consciousness begins; and whether computers can achieve conscious states.

In common parlance, consciousness denotes being awake and responsive to the environment, in contrast to being asleep or in a coma.

Also Wikipedia states:

The term subconscious is defined as existing or operating in the mind beneath or beyond conscious awareness. The word was coined by the psychologist Pierre Janet, who credited it with a hidden level ofawareness and automatism. In the strict psychological sense, the adjective is defined as “operating or existing outside of consciousness“. The term also appears in Sigmund Freud’s very early work, to denote the unconscious mind but was soon eliminated due to its ambiguity. It may also be used to describe the preconscious, information contained in the mind, which although not presently in the conscious, may be recalled by “directing attention to them”, such as memories not being recalled at present, but still available to be recalled at will. Use of the term “subconscious” is avoided within academic psychology but remains popular in common use and other academic disciplines.

And

Many observers throughout history have argued that there are influences on consciousness from other parts of the mind. These observers differ in the use of related terms, including: unconsciousness as a personal habit; being unaware and intuition. Terms related to semi-consciousness include: awakening, implicit memory, the subconscious,subliminal messages, trance, and hypnosis. Although sleep, sleep walking, delirium and coma may signal the presence of unconscious processes, these processes are not the unconscious mind. Science is also in its infancy in exploring the limits of consciousness.

For the preconscious Wikipedia states:

In Freudian psychoanalysis, the word preconscious is applied to thoughts which are unconscious at the particular moment in question, but which are not repressed and are therefore available for recall and easily capable of becoming conscious.

‘Preconscious’ thoughts are thus ‘unconscious’ in a merely ‘descriptive’ sense, as opposed to a ‘dynamic’ one.

Classical psychoanalysis therefore permits itself to

“distinguish two kinds of unconscious — one which is easily, under frequently occurring circumstances, transformed into something conscious, and another with which this transformation is difficult and takes place only subject to a considerable expenditure of effort or possibly never at all. [. . .] We call the unconscious which is only latent, and thus easily becomes conscious, the ‘preconscious’, and retain the term ‘unconscious’ for the other”. [Freud, New Introductory Lectures on Psychoanalysis (1932)]

As explained by David Stafford-Clark,

“If consciousness is then the sum total of everything of which we are aware, pre-consciousness is the reservoir of everything we can remember, all that is accessible to voluntary recall: the storehouse of memory. This leaves the unconscious area of mental life to contain all the more primitive drives and impulses influencing our actions without our necessarily ever becoming fully aware of them, together with every important constellation of ideas or memories with a strong emotional charge, which have at one time been present in consciousness but have since been repressed so that they are no longer available to it, even through introspection or attempts at memory”. [David Stafford-Clark, What Freud Really Said (1965)]