This chapter introduces key concepts, including lifelong education, lifelong learning and recurrent education, and outlines key issues that have shaped this field. First, the origins and main understandings of lifelong learning and cognate concepts from the 1970s are discussed. Commonalities across these key concepts are highlighted, as are crucial differences that create conflicting understandings. A schema is presented to compare and classify different understandings of the concepts. Second, the resurgence of interest in lifelong learning from the 1990s onward is traced, and the reasons for it, including economic competitiveness, globalization, and the focus on knowledge creation, are discussed. A novel emphasis on learning has resulted from the rise to preeminence of the concept “lifelong learning.” Diverse understandings about learning have fueled ongoing disagreements about the role and significance of lifelong learning. Some interpretations limit the scope of learning to the kinds characteristic of formal education systems. Others regard lifelong learning as covering all kinds of informal learning. These differing valuations of learning underpin much of the ongoing disputes about lifelong learning. The emerging notion of the learning society is also outlined and discussed. It features the same conceptual conflicts that marked the earlier concepts. Third, four common criticisms of lifelong learning are outlined and discussed. All criticisms are shown to make assumptions about learning that favor formal learning, while marginalizing informal learning. Thus, even today, understanding of lifelong learning and its significance is hampered by tendencies to adhere to narrow views of learning that many people develop unreflectively from their experiences of formal education.