All Agile processes rely on a prioritized backlog. This is a list of implementation tasks or "stories," sorted so that the tasks that should be worked on next are on the top.

The first job of a product owner is to make sure there are items on top of the backlog that are ready for implementation. They need to be important, and they need to be fully defined as stories with use cases.

When you start a project, you build the backlog with "roadmapping." You brainstorm about all of the things that you want to do, and then you sort them so that the tasks or stories on the top represent a minimum useful release.

In a continuous process, you "pull" tasks off the backlog when you are ready to work on them, like this:

In a distributed process, the backlog should always be represented in an online ticketing or issue tracking system. That way everyone on the team can see the items on the top of the list and discuss them.