For Extension educational programs to meet the educational needs of today's youths, families, and communities, Extension needs to expand "what counts" as learning. The purpose of this article is to define learning in the context of Extension. We summarize key aspects of the educational research literature by comparing two prevailing metaphors for learning: acquisition and participation. On the basis of the two metaphors, we developed a definition of learning, and we discuss the related implications for program and curriculum development, pedagogy, professional development, and assessment of learning.