I'm a Product Manager based in Istanbul.
A roadmap milestone is a date that specifies an event or deadline that the product manager wants the team to be aware of. They exist to highlight internal and external goals.
A feature request is a suggestion, message, or request from a user regarding a particular feature that your organization wishes to implement. Feature requests can be used to decide how to iterate on an existing product.
Personas are used to help a product manager (or product developers) understand the characteristics, behaviors, goals, and responsibilities of a particular segment of users. We can say that persona is actually an analysis process.
