Experience is the knowledge or mastery of an event or subject gained through involvement in or exposure to it.[1] Terms in philosophy, such as "empirical knowledge" or "a posteriori knowledge," are used to refer to knowledge based on experience. A person with considerable experience in a specific field can gain a reputation as expert.The concept of experience generally refers to know-how or procedural knowledge, rather than propositional knowledge: on-the-job training rather than book-learning.