The document discusses the history of software requirements and the evolution from waterfall to agile approaches. Waterfall led to high failure rates due to incomplete, changing requirements and lack of user involvement. Agile methods address these issues by starting with prioritized backlogs of user stories, collaborating with users in sprints to refine requirements and build shippable software incrementally, and accepting that requirements will change. Agile focuses on individuals, interactions, working software and responding to change over processes, tools, documentation and plans.