Knowledge is a familiarity with someone or something, which can include
facts,
information,
descriptions, or
skills acquired through
experience or
education. It can refer to the theoretical or practical understanding of a subject. It can be implicit (as with practical skill or expertise) or explicit (as with the theoretical understanding of a subject); it can be more or less formal or systematic. In
philosophy, the study of knowledge is called
epistemology; the philosopher
Plato famously defined knowledge as "
justified true belief. " However, no single agreed upon definition of knowledge exists, though there are numerous theories to explain it.
Knowledge acquisition involves complex
cognitive processes: perception, communication, association and reasoning; while knowledge is also said to be related to the capacity of
acknowledgment in human beings.