Projects View shows all your projects in alphabetical order. Projects may have sub-projects, for example in the screenshot Administration has sub-projects Bills and Purchases.
By clicking on a project its tasks are shown, in the order in which they need to be done. In the screenshot the very important Lunch project is highlighted and its tasks are shown. Tasks may be moved up and down the order using the arrow buttons on the toolbar.
Projects and tasks can be created, modified and deleted only from the Projects View.
Tasks View shows all the current tasks, from across all projects. All the top level tasks are shown together, then all the second level ones, and so on. So you know at once what tasks you need to work on to make sure that all your projects are progressed.