This chapter examines the essential role of libraries as traditionally recognised information and documentation institutions. They serve as key actors in the preservation, archiving, selection, organisation (in accordance with internationally accepted scientific and methodological standards), dissemination and production of scientific and cultural knowledge. In essence, libraries function as hubs where data, information, and knowledge are processed and made accessible. Globally, they are acknowledged as fundamental institutions supporting all forms of education, including formal and non-formal learning across all types of schools, as well as informal and cultural education in the name of democracy and equal access to information. They also play a central role in lifelong learning, contributing to both personal and professional development. Following a brief overview, this chapter introduces key concepts such as data, information, knowledge, knowledge management, learning, and organisational learning. It further positions libraries as learning organisations, actively engaged in knowledge processes within the institutions of which they form an integral part. The chapter aims to address two theoretical research questions: