An aptitude is a component of a competence to do a certain kind of work at a certain level. Outstanding aptitude can be considered "talent". An aptitude may be physical or mental. Aptitude is inborn potential to do certain kinds of work whether developed or undeveloped. Ability is developed knowledge, understanding, learned or acquired abilities (skills) or attitude. The innate nature of aptitude is in contrast to skills and achievement, which represent knowledge or ability that is gained through learning.
According to Gladwell (2008) and Colvin (2008) often it is difficult to set apart an outstanding performance merely because of talent or simply because of hard training. Talented people as rule show high results immediately in few kinds of activity, but often only in single direction or genre.
Aptitude and intelligence quotient are related, and in some ways differing views of human mental ability. Unlike the original idea of IQ, aptitude often refers to one of many different characteristics which can be independent of each other, such as aptitude for military flight, air traffic control, or computer programming. This approach measures a variety of separate skills, similar to the theory of multiple intelligences and Cattell–Horn–Carroll theory and many other modern theories of intelligence. In general, aptitude tests are more likely to be designed and used for career and employment decisions, and intelligence tests are more likely to be used for educational and research purposes. However, there is a great deal of overlap between them, and they often measure the same kinds of abilities. For example, aptitude tests such as the Armed Services Vocational Aptitude Battery measure enough aptitudes that they could also serve as a measure of general intelligence.