In Agile software development, an epic is a large, high-level user story that represents a large feature or theme that can be broken down into smaller, more manageable user stories. Epics are used to capture large, complex requirements that are too big to fit into a single user story, and often span multiple sprints or iterations.

An epic represents a significant effort that will require significant resources and time to complete, and may involve multiple teams or stakeholders. Epics are typically used to plan and prioritize work at a high level, and are broken down into smaller, more detailed user stories during the backlog refinement process.

Epics are a key part of Agile methodologies such as Scrum and Kanban, and are used to help teams manage and prioritize their work in a flexible and iterative manner. By breaking down large features into smaller user stories, teams can work more efficiently and deliver value to customers more quickly.