This is an introductory-level post but offers a fairly comprehenmsive account of the distinction between 'pedagogy' and 'andragogy', summarizing from Malcolm Knowles's The Making of an Adult Educator. The latter term is typically used to refer to the teaching process in adult learning, and it's different because adults have different characteristics as learners: they have more life experience, are often more disciplined, and can be more self-directed. But also, "it seems as though pedagogy has shifted to look more and more like the andragogy that Knowles describes. The primary difference between child and adult learners? Their motivation to learn… sometimes."