Issue Manager provides a range of actions that allow you to work on issues. You can, for example, mark issues as fixed or implemented, you can indicate that you need more info or that an issue is no longer an issue, and so on.
The buttons for these actions display on the right side of the Issue Details page. For a list of all available actions, see Actions for Working with Issues. The list of issues varies depending on the state of the issue and on the permissions of a certain user. Many actions can be configured and customized by the Issue Manager Administrator.