Agile is an iterative and incremental methodology focusing on quick product delivery and adaptability to changes, with active customer involvement throughout the process. Scrum, as a framework within Agile, involves a Scrum team consisting of a product owner, Scrum master, development, and QA teams, each with distinct roles and responsibilities. Key concepts include sprints for task completion, backlogs for managing user stories, and various Scrum-specific meetings to facilitate communication and progress tracking.