Typically the raw materials will include physical stimuli, day's residues (elements from the dayu's waking state that appear either in the dream itself or in the dreamer's free associations) and dream-thought (latent content).
Considerations of representability select, transform and censor dream-thoughts so as to allow them to be represented - usually in the form of visual images - whilst secondary revision arranges them into a relatively coherent scenario or narrative.
The dream-work does not create anything and merely transform existing material.
Freud introduced the notion of "dream work" to clearly emphasize that the dream is not the result, as was generally thought to be the case, of a weakened state of mental activity producing incoherent fragments, but, on the contrary, the outcome of very complex psychic work.
This was the notion that was articulated in The Interpretation of Dreams (1900a), based on a fundamental hypothesis: the dream represents a fulfillment of desires that are repressed in waking life, but this realization is typically disguised so as to pass through censorship during sleep. The "dream work" is responsible for this disguise.
The "materials" used in this process are essentially of two types: residues of the day, that is to say "mnemonic traces" of events, thoughts, affects, etc., of waking life (usually recent), and bodily sensations during sleep (hunger, thirst, pain, etc., but particularly erotic excitation).
The source of the dream, however, is to be found in conflicts and wishes of childhood—oedipal conflicts prominent among them .
The dream work proceeds in two phases.
The first phase is that of the primary processes: "condensation," resulting in compressing into a single image disparate, even contradictory material (events, personages, representations, affects, etc.); "displacement," whereby an affectively neutral representation is substituted for another, and finally visual imagery is primarily the mode of representation for thoughts, affects, and sensation.
There is the passage into images itself, or "representability": the dream is made up of essentially visual sensorial images.
The first phase of the dream produces the manifest content, which is the unrecognizable translation of the "latent thoughts" that can be made conscious through analysis.
However, the manifest content has to be subjected to a secondary revision upon awakening in order to create a superficial coherence in the remembered and repeated dream.
It is significant that while Freud described these primary and secondary processes as the two phases of the dream work, he also considered them as the two processes governing mental activity: the "primary processes," characterized by the free flowing of an unbound energy; and "secondary processes," dominated by rational intellectual activity and bound energy.
Consequently, there is a wide chasm between the primary and secondary processes that can be revealed by dissection of the dream work.