The work column shows the estimated amount of time spent on a project, task, or phase. In the screenshot below, you’ll notice how much time has should be put into every individual task, phase, and milestone. All of these hours are added together to give you the total amount of work done in the project row. Adding a resource will also add to the estimated amount of work that needs to be done.
To change the dates for a task or phase, select the three dots located in the actions column of the one you want to edit. This will open the “Edit Task” window, where you can change the start and end dates. As a result, the duration of the project and phase/task are also changed.