By default, no matter which layout you decide to work with (list, calendar, roadmap, or board), your task will open as a side panel to the right of your screen:

When a task is created or opened, you can add whatever you like, from status to attachments, to a description (and more). You can also choose how to view tasks and set your default view of tasks going forward.

For example, you can choose to adjust your task view from the default Side panel appearance to Fullscreen:

or Overlay:

To change the way your tasks appear, open a task and click the screen icon at the top right of your task (located beside the close, or "x" icon). A display mode menu will appear:

Hover over Change default for a sub-menu that will allow you to change your default task settings and keep them in either Side panel, Fullscreen or Overlay format:

If you would like to return to your list, calendar, board, or roadmap view of tasks (from fullscreen or overlay task views), simply click on the "x" at the top corner of the task you have open, or press escape on your keyboard.