Radicalism is a concept and field of study concerned with ideologies, movements, and actions advocating for fundamental, often rapid or extreme, change to existing socio-political, economic, or institutional structures. It investigates the origins, motivations, characteristics, processes, and impacts of beliefs and behaviors that seek systemic transformation, typically involving a rejection of established norms and a commitment to root-and-branch reform or revolution. Its significance lies in its capacity to illuminate drivers of societal conflict, political evolution, and historical change.