An understanding is the limit of a conceptualization. To understand something is to have conceptualised it to a given measure.
Thomas Edison believed that the concept of understanding comes from the two simple words under and stand. When one acknowledges that she/he stands below someone or something else, she/he makes him/herself receptive to obtain and retain information from it, thereby allowing for understanding to occur.
It may be more convenient to use an operational or behavioural definition, that is, to can say that somebody who reacts appropriately to X understands X. For example, one understands Swahili if one correctly obeys commands given in that language. This approach, however, may not provide an adequate definition. A computer can easily be programmed to react appropriately to commands, but there is a disagreement as to whether or not the computer understands the language (see the Chinese room argument).
In the cognitive model presented by MBTI, the process of introverted thinking (Ti) is thought to represent understanding through cause and effect relationships or correlations. One can construct a model of a system by observing correlations between all the relevant properties (e.g. The output of a NAND gate relative to its inputs). This allows the person to generate truths about the system and then to apply the model to demonstrate his or her understanding. A mechanic for example may randomly, or algorithmically probe the inputs and outputs of a black box to understand the internal components through the use of induction. INTP, ISTP, ESTP, and ENTP all use Ti and are usually the best of the 16 types at understanding their material environment in a bottom-up manner. These types may enjoy mechanics and digital electronics because of the 1 to 1 correlation between cause and effect relationships in these fields. Understanding is not limited to these types however as other types demonstrate an identical process, although in other planes of reality; ie. Social, Theological and Aesthetic. A potential reason for the association of understanding with the former personality types is due to a social phenomenon for asymmetrical distribution of gratification. In the field of engineering, engineers probe or study the inputs and outputs of components to understand their functionality. These components are then combined based on their functionality (similar to computer programming) to create a larger, more complex system. This is the reason why engineers attempt to subdivide ideas as deep as possible to obtain the lowest level of knowledge. This makes their models more detailed and flexible. It may be useful to know the formulas that govern an ideal gas, but to visualise the gas as being made up of small moving particles, which are in turn made up of even smaller particles, is true understanding. People who are understanding (through the use of Ti) usually value objects and people based on usefulness, as opposed to the people who use extroverted thinking (Te) who view people or things as having a worth. In order to test one's understanding it is necessary to present a question that forces the individual to demonstrate the possession of a model, derived from observable examples of that model's production or potential production (in the case that such a model did not exist beforehand). Rote memorization can present an illusion of understanding, however when other questions are presented with modified attributes within the query, the individual cannot create a solution due to a lack of a deeper representation of reality.
Another significant point of view holds that knowledge is the simple awareness of bits of information. Understanding is the awareness of the connection between the individual pieces of this information. It is understanding which allows knowledge to be put to use. Therefore, understanding represents a deeper level than simple knowledge.