How to Write a Good User Story: with Examples & Templates

What is a User Story? User Story is a small (actually, the smallest) piece of work that represents some value to an end user and can be delivered during a sprint.
As a [type of user], I want [an action] so that [a benefit/a value]

Great User Stories always fit the INVEST set of criteria by Bill Wake:

Independent – they can be developed in any sequence and changes to one User Story don’t affect the others.
Negotiable – it’s up for the team to decide how to implement them; there is no rigidly fixed workflow.
Valuable – each User Story delivers a detached unit of value to end users.
Estimable – it’s quite easy to guess how much time the development of a User Story will take.
Small – it should go through the whole cycle (designing, coding, testing) during one sprint.
Testable – there should be clear acceptance criteria to check whether a User Story is implemented appropriately.
Don’t forget to add an acceptance criteria = a set of conditions that are used to confirm when a Story is completed.

Is there something else? An Epic is a high-level body of work that bands together with a group of related Stories.

Article also covers:
What Are the Benefits of Creating User Stories?
How to Write User Stories: Our Workflow
Who is responsible for creating a User Story?
When are User Stories created?
What are the steps to write great Agile User Stories?
Step 1: Think of the “Who”
Step 2: Think of the “What”
Step 3: Think of the “Why”
Step 4: Discuss a Story
Conclusion

Author = Andrew Bondarenko (Stormotion)

https://stormotion.io/blog/how-to-write-a-good-user-story-with-examples-templates/