How are Epic, User Story and Tasks different from one another in the context of Scrum?
Epic : It is something so large that it will almost certainly not fit into a sprint, is unclear in terms of client requirements, and should be split down into stories. Epics are often defined at the early stages of product road mapping and then broken into stories in the product backlog when additional information becomes available.
User Story : A story is anything actionable that can be fit into a sprint. These are INVEST criteria-based story points and definitions. By the end of an iteration, stories should give a vertical slice of functionality to the client that is both valuable and complete. Typically, stories are developed throughout the product development process, particularly prior to iteration planning and throughout higher-level product road mapping.
Task : They are the decomposed parts of a story that define how the story will be finished. If needed, tasks can be estimated by the hour. Tasks are typically defined by the individuals who execute the job, whereas stories and epics are typically developed by the customer. Because tasks are temporary, they are produced within the confines of an iteration.
