Project Roadmap
The project roadmap shows a list of work items to be completed grouped by milestone. By clicking on the milestone header you can expand of collapse a list of issues. The milestone header also shows the number of issues resolved and a progress bar.If all issues for a milestone are marked as resolved or closed (at least one issues status must be set as "Is Closed" status in the project settings) then it will not be shown on the roadmap.
For agile teams, the project roadmap can be used as the backlog.