Experience is the process through which organisms the world around them. Experiences can be accompanied by active on the part of the person having the experience, although they need not be.Experience is the primary subject of various subfields of , including the , the , and .Several different senses of the word "experience" should be distinguished from one another. In the sense of the word under discussion here, "experience" means something along the lines "observation". In this sense of the word, gained from experience is called "a posteriori knowledge".