Andragogy is the theory and practice of education of adults.
Two primary understandings of ‘andragogy’ currently exist:
The science of understanding (= theory) and supporting (= practice) lifelong and life-wide education of adults.
In the tradition of Malcolm Knowles, andragogy is a specific theoretical and practical approach, based on a humanistic conception of self-directed and autonomous learners with teachers acting as 'facilitators' of learning.
The term is conceived to apply to adults as distinct from children whose learning is described by the term "pedagogy".
Whereas children learn based on content, adults are highly motivated when solving problems or tasks related to their daily basis routine. Furthermore, their experiences are valued and adults feel motivated when the activities are relevant to them.
This link has a helpful overview of the term if you want to read more about it: https://infed.org/mobi/andragogy-what-is-it-and-does-it-help-thinking-about-adult-learning/