The Gantt Chart view in the Tasks tab provides a visual representation of your tasks. The horizontal axis represents the time span of the project, broken down into increments (such as minutes, hours, days, weeks, months, and years) and the vertical axis represents the project tasks. Tasks can run sequentially, in parallel, or overlapping.
You can drag a task to different dates, or click and drag on either end of the task to extend or shorten its duration. Any changes are automatically updated in the Task view. Similarly, modifying a field in the Tasks view modifies the corresponding field on the Gantt Chart view.