Map/territory relation
The map is not the territory is a remark by Alfred Korzybski, encapsulating his view that an abstraction derived from something, or a reaction to it, is not the thing itself, e.g., the pain from a stone falling on your foot is not the stone; one's opinion of a politician, favorable or unfavorable, is not that person; a metaphorical representation of a concept is not the concept itself; and so on. A specific abstraction or reaction does not capture all facets of its sourcee.g., the pain in your foot does not convey the internal structure of the stone, you don't know everything that is going on in the life of a politician, etc.and thus may limit an individual's understanding and cognitive abilities unless the two are distinguished. Korzybski held that many people do confuse maps with territories, in this sense.
Korzybski's dictum ("The map is not the territory") is also cited as an underlying principle used in neuro-linguistic programming, where it is used to signify that individual people in fact do not in general have access to absolute knowledge of reality, but in fact only have access to a set of beliefs they have built up over time, about reality. So it is considered important to be aware that people's beliefs about reality and their awareness of things (the "map") are not reality itself or everything they could be aware of ("the territory"). The originators of NLP have been explicit that they owe this insight to General Semantics.

# The map/territory relationship
Gregory Bateson, in "Form, Substance and Difference," from Steps to an Ecology of Mind (1972), elucidates the essential impossibility of knowing what the territory is, as any understanding of it is based on some representation:
We say the map is different from the territory. But what is the territory? Operationally, somebody went out with a retina or a measuring stick and made representations which were then put on paper. What is on the paper map is a representation of what was in the retinal representation of the man who made the map; and as you push the question back, what you find is an infinite regress, an infinite series of maps. The territory never gets in at all.  Always, the process of representation will filter it out so that the mental world is only maps of maps, ad infinitum.
Elsewhere in that same volume, Bateson points out that the usefulness of a map (a representation of reality) is not necessarily a matter of its literal truthfulness, but its having a structure analogous, for the purpose at hand, to the territory. Bateson argues this case at some length in the essay "The Theology of Alcoholics Anonymous".
To paraphrase Bateson's argument, a culture that believes that common colds are transmitted by evil spirits, that those spirits fly out of you when you sneeze, can pass from one person to another when they are inhaled or when both handle the same objects, etc., could have just as effective a "map" for public health as one that substitutes microbes for spirits.
Another basic quandary is the problem of accuracy.
In  "On Exactitude in Science", Jorge Luis Borges describes the tragic uselessness of the perfectly accurate, one-to-one map:
In time, those Unconscionable Maps no longer satisfied, and the Cartographers Guild drew a Map of the Empire whose size was that of the Empire, coinciding point for point with it. The following Generations, who were not so fond of the Study of Cartography saw the vast Map to be Useless and permitted it to decay and fray under the Sun and winters.
In the Deserts of the West, still today, there are Tattered Ruins of the Map, inhabited by Animals and Beggars; and in all the Land there is no other Relic of the Disciplines of Geography.
With this apocryphal quotation of Josiah Royce, Borges describes a further conundrum of when the map is contained within the territory, you are led into infinite regress:
The inventions of philosophy are no less fantastic than those of art: Josiah Royce, in the first volume of his work The World and the Individual (1899), has formulated the following: 'Let us imagine that a portion of the soil of England has been levelled off perfectly and that on it a cartographer traces a map of England. The job is perfect; there is no detail of the soil of England, no matter how minute, that is not registered on the map; everything has there its correspondence. This map, in such a case, should contain a map of the map, which should contain a map of the map of the map, and so on to infinity.' Why does it disturb us that the map be included in the map and the thousand and one nights in the book of the Thousand and One Nights? Why does it disturb us that Don Quixote be a reader of the Quixote and Hamlet a spectator of Hamlet? I believe I have found the reason: these inversions suggest that if the characters of a fictional work can be readers or spectators, we, its readers or spectators, can be fictions.
An alternative reason why we are bothered by the conundrum of infinite regress or the conundrum of maps within maps is that we fail to see that the concept of a "map of a map" is the same thing as the concept of a "map of a map of a map." In both cases, the concept is a metaphor for the faculty of reflection. We fail to distinguish that one's capability of reflecting is an enduring perspective and not simply a fleeting act of examining something. Each time I examine myself examining something (or in turn reflect upon my examination of myself examining my examination) I am exercising the same enduring ability. Husserl referred to this ability as the "transcendental ego," the mind's eye or the capability of a human to reflect and abstract. Standing between two mirrors, you will not be fooled by the infinite regress of the reflection of yourself in a mirror within a mirror within a mirror (ad infinitum) precisely because you are able to see (understand) that you are looking at mirrors facing each other and are not looking at an infinite queue of dopplegangers. Likewise characters of a fictional work can be readers or spectators or any other fiction that can be imagined precisely because they are fictions, but the fact that you can reflect upon your ability to examine yourself and your thoughts means you are capable of abstraction and need not suggest that you too are a fictional character in a fictional work.
Neil Gaiman retells the parable in reference to storytelling in Fragile Things (it was originally to appear in American Gods):
One describes a tale best by telling the tale. You see? The way one describes a story, to oneself or the world, is by telling the story. It is a balancing act and it is a dream. The more accurate the map, the more it resembles the territory. The most accurate map possible would be the territory, and thus would be perfectly accurate and perfectly useless. The tale is the map that is the territory.
The development of electronic media blurs the line between map and territory by allowing for the simulation of ideas as encoded in electronic signals, as Baudrillard argues in Simulacra & Simulation:
Today abstraction is no longer that of the map, the double, the mirror, or the concept. Simulation is no longer that of a territory, a referential being or substance. It is the generation by models of a real without origin or reality: A hyperreal. The territory no longer precedes the map, nor does it survive it. It is nevertheless the map that precedes the territory - precession of simulacra - that engenders the territory. (Baudrillard, 1994, p. 1)

# "The map is not the territory"
The expression "the map is not the territory" first appeared in print in a paper that Alfred Korzybski gave at a meeting of the American Mathematical Society in New Orleans, Louisiana in 1931: 
- A) A map may have a structure similar or dissimilar to the structure of the territory...
- B) A map is not the territory.
It is used as a premise in Korzybski's General Semantics, and in neuro-linguistic programming.
The Belgian surrealist artist Rene Magritte illustrated the concept of "perception always intercedes between reality and ourselves" in a number of paintings including a famous work entitled The Treachery Of Images, which consists of a drawing of a pipe with the caption, Ceci n'est pas une pipe ("This is not a pipe").
This concept occurs in the discussion of exoteric and esoteric religions. Exoteric concepts are concepts which can be fully conveyed using descriptors and language constructs, such as mathematics. Esoteric concepts are concepts which cannot be fully conveyed except by direct experience. For example, a person who has never tasted an apple will never fully understand through language what the taste of an apple is. Only through direct experience (eating an apple) can that experience be fully understood.
Lewis Carroll, in Sylvie and Bruno (1889), made the point humorously with his description of a fictional map that had "the scale of a mile to the mile." A character notes some practical difficulties with such a map and states that "we now use the country itself, as its own map, and I assure you it does nearly as well."
In a sort of counterpoint to Lewis Carroll, the University of Cambridge economist Joan Robinson (1962) emphasized the disutility of 1:1 maps and other overly detailed models: "A model which took account of all the variegation of reality would be of no more use than a map at the scale of one to one."
Korzybski's argument about the map and the territory also influenced the Belgian surrealist writer of comics Jan Bucquoy for a storyline  in his comic Labyrinthe: a map can never guarantee that one will find the way out, because the accumulation of events can change the way one looks at reality.
Historian of religions J. Z. Smith wrote a book entitled Map is not Territory: Studies in the History of Religions (1978, University Of Chicago Press 1993 paperback: ISBN 0-226-76357-9).