Projection means the expulsion of a subjective content into an object; it is the opposite of introjection. Accordingly it is a process of dissimilation, by which a subjective content becomes alienated from the subject and is, so to speak, embodied in the object.
Jung defines the subject as the origin point from which contents are expelled into objects, making subjectivity constitutively relational and perpetually at risk of self-alienation through projection.
, Psychological Types, 1921thesis