A Burndown Chart shows the actual and estimated amount of work to be done in a sprint. The horizontal x-axis in a Burndown Chart indicates time, and the vertical y-axis indicates cards (issues).
Use a Burndown Chart to track the total work remaining and to project the likelihood of achieving the sprint goal. By tracking the remaining work throughout the iteration, a team can manage its progress and respond accordingly.
This page only applies to Scrum boards.
To view the Burndown Chart:
Screenshot: Burndown Chart (click to enlarge)
Click Non Working Days to highlight days when your team won't be working.