Explain about Epic and User Stories

Epic :
An agile epic is a body of work that can be broken down into specific tasks (called user stories) based on the needs/requests of customers or end-users. Epics are an important practice for agile and DevOps teams.
When adopting agile and DevOps, an epic serves to manage tasks. It's a defined body of work that is segmented into specific tasks (called “stories,” or “user stories”) based on the needs/requests of customers or end-users.
Epics are a helpful way to organize your work and to create a hierarchy. Epics help teams break their work down, while continuing to work towards a bigger goal.
User Story :
A user story is an informal, general explanation of a software feature written from the perspective of the end user. Its purpose is to articulate how a software feature will provide value to the customer.
A user story is the smallest unit of work in an agile framework. It’s an end goal, not a feature, expressed from the software user’s perspective.
The purpose of a user story is to articulate how a piece of work will deliver a particular value back to the customer. User stories are a few sentences in simple language that outline the desired outcome. User stories are also the building blocks of larger agile frameworks like epics and initiatives. Epics are large work items broken down into a set of stories. Generally, a story is written by the product owner, product manager, or program manager and submitted for review.