The principal categories of Lacanian psychoanalysis in the structuring of the psyche are the imaginary, the symbolic, and the real. The imaginary (imaginaire) refers to perceived or imagined images in conscious and unconscious thought, sensible and intelligible forms; picture thinking (Vorstellung), dream images or manifest content, and conscious ego in discursive thought. The symbolic (symbolique) refers to the signifying order, signifiers, in language, which determine the subject; it refers to the unconscious, and the intellectual, the logos endiathetos and the logos prophorikos. It is the relation between the imaginary and symbolic in conscious and unconscious thought which is the core of Lacanian psychoanalysis. The real (réel) is that which is neither imaginary nor symbolic in conscious or unconscious thought, and which is inaccessible to psychoanalysis. It is only proposed as an algebraic concept, as it can not even be conceived, like the One of Plotinus, which cannot be thought or described, but which exists as an absence in the symbolic order (language) in the same way that the unconscious exists as an absence in conscious thought. The real is as the umbilical cord of the Freudian unconscious, which Lacan reframes as constituted by the symbolic.
Hendrix, J. S. (2019). The Imaginary and Symbolic of Jacques Lacan. Retrieved from https://docs.rwu.edu/saahp_fp/45