Classical theory has remained unchallenged for so long because it seemed intuitively correct and has great explanatory power. The theory also postulates that people`s theories about the world influence their conceptual knowledge of the world. Therefore, analyzing people`s theories can give insight into their concepts. In this sense, “theory” means the mental explanation of an individual rather than a scientific fact. This theory criticizes the fact that classical theory and prototype theory rely too much on similarities and use them as a sufficient constraint. This suggests that theories or mental understanding contribute more to what belongs to a group than weighted similarities, and that a cohesive category is formed more by what makes sense to the tax collector. The weights assigned to traits fluctuate and vary depending on the context and the experimental task demonstrated by Tversky. For this reason, similarities between members may be collateral rather than causal.  The study of concepts and conceptual structure falls within the disciplines of linguistics, philosophy, psychology and cognitive science.  Concepts can be organized into a hierarchy whose higher levels are called “parent” and lower levels are called “child”. In addition, there is the “basic” or “intermediate” level, where people are most likely to categorize a concept.  For example, a basic term would be “chair” with its superior “furniture” and subordinate “armchair”. There is a lot of discussion about the most effective theory in concepts.
Another theory is that of semantic pointers that use perceptual and motor representations and these representations are like symbols.  In the simplest case, a term is a noun or label that considers or treats an abstraction as if it had a concrete or material existence, such as a person, place or thing. It can represent a natural object that exists in the real world, such as a tree, an animal, a stone, etc. It can also name an artificial (artificial) object such as a chair, computer, house, etc. Abstract ideas and areas of knowledge such as freedom, equality, science, happiness, etc. are also symbolized by concepts. It is important to realize that a concept is only a symbol, a representation of abstraction. The word should not be confused with the question. For example, the word “moon” (a concept) is not the large, bright object that changes shape in the sky, but represents only that celestial object. Concepts are created (named) to describe, explain and grasp reality as it becomes known and understood.
There are discussions about the relationship between concepts and natural language.  However, it is necessary to begin at least by understanding that the term “dog” is philosophically different from the things in the world grouped by this concept – or the reference class or extension.  Terms that can be likened to a single word are called “lexical concepts”.  Concepts may be precise or inaccurate.  When the mind makes a generalization such as the concept of the tree, it extracts similarities from many examples; Simplification allows for higher-level thinking. A concept is instantiated (objectified) by all its actual or potential instances, whether they are real-world things or other ideas. Concepts are thought to be stored in long-term cortical memory, as opposed to episodic memory of specific objects and events that they abstract and store in the hippocampus. Evidence for this separation comes from hippocampus-damaged patients like HM patient. The abstraction of the events and objects of the hippocampus of the day into cortical concepts is often thought of as the underlying computation (certain stages of) sleep and dreaming.
Many people (starting with Aristotle) report dream memories that seem to mix the events of the day with analogous or related historical concepts and memories, suggesting that they have been sorted or organized into more abstract concepts. (“Sorting” is itself another word for concept, and so “sorting” means organizing oneself into concepts.) Concepts are studied as components of human cognition in the cognitive science disciplines of linguistics, psychology, and philosophy, where there is an ongoing debate about whether all cognition should be done through concepts. Concepts are regularly formalized in mathematics, computer science, databases and artificial intelligence. Examples of specific common conceptual classes in these areas are classes, schemas, or categories. In informal usage, the word concept often means just an idea. The term “concept” dates back to the years 1554-60 (Latin conceptum – “something designed”).  English Language Learners Definition of the concept (entry 2 of 2) The semantic view of concepts suggests that concepts are abstract objects. In this perspective, concepts are abstract objects of a category of a person`s mind and not mental representations.
 Prototypes also deal with the nature of things and the extent to which they belong to a category. There have been a number of experiments that have looked at questionnaires in which participants were asked to rate something based on the extent to which it belongs in a category.  This question contradicts classical theory because something is a member of a category or not.  This type of problem is associated in other areas of linguistics such as phonology with an illogical question such as “Is /i/ or /o/ a better vowel?” The classical approach and Aristotelian categories may be a better descriptor in some cases.  Kant argued that the human mind possesses pure or a priori concepts. Instead of being abstract from individual perceptions as empirical concepts, they arise in the mind itself. He called these concepts categories, in the sense of the word meaning predicate, attribute, characteristic, or quality. But these pure categories are predicates of things in general, not of a particular thing. According to Kant, there are twelve categories that make up the understanding of phenomenal objects.
Each category is the common predicate to several empirical concepts. In order to explain how an a priori concept can refer to individual phenomena analogous to an a posteriori concept, Kant used the technical concept of schema. He was of the opinion that the representation of the concept as an abstraction of experience was only partially correct. He called these concepts that arise from abstraction “a posteriori concepts” (that is, concepts that arise from experience).