Releasing a version is the culmination of your team's hard work. It may be the result of many iterations of work across a number of months. As the iteration manager, it will be your job to ensure that all the work is complete for the release, and to coordinate the activities needed to release the version.
As described in Configuring versions in a Scrum project and Configuring versions in a Kanban project, versions are handled differently in Scrum and Kanban projects. A version in a Scrum project is pre-planned and is released when the planned work is complete. In a Kanban project, a version can be released at any time — the version will contain all issues that are complete at that time.