When Should Use Which? User Story / Use Case / Feature / Backlog Item

We always come across these terms in software development. Sometimes people a piece of software feature — requirement/ use case, backlog items ….

What is the convention of the software people for using that or which?

Different Method / Different Term

The different methods or processes use different terminology to refer to features. Ultimately, the goal is the same — to deliver business value regularly in small increments, and sooner rather than later.

• Agile / Scrum calls a feature a Backlog Item, which tends to be larger grained and can also include non-feature items such as ‘set up production hardware’, or ‘research xyz options’.
• XP calls a feature a User Story, which lends itself to a particularly helpful approach to defining functionality.
• DSDM calls a feature a Requirement, which can also include more than just system features.
• Agile UP / UML practitioners use Requirements and Use Cases to define features.