When task steps get executed within a process instance, tasks are created and assigned to users. These tasks can be acted on using the task UI.

By default, the displayed list of tasks is for the currently logged in user and tasks are sorted by the date. As an administrative user, you have the option to view and act on the task assigned to other users also. Tasks assigned to other users can be viewed by the user or process instance.

Click on a selected task to render its contents.  The rendered task can be completed or rejected with a comment.  Users can also upload and assign files to the task by using the “Attach Files” section. All the attached files will be displayed below on the task page as shown above. The task can be saved with comments to indicate work in progress by using the scroll bar feature. The UI for the task looks as follows. The task due date in red color indicates the task is already due and in this case, the task completion date is same as Assigned On date. 

Click on (+) sign to expand and collapse the task details. To give complete visibility of a task, a task now has a percentage of completion, where you can set what % is completed.  This % is displayed on the task lists and reporting, it's an easy way to see how much work is done on the task.

Click on the "Clock" icon to view the "Task History" popup; which provides an audit log of the task activity since the datetime created. 

Click on task navigation icon to render the process instance. Alternate is to navigate to Run - Process Instance - select process instance from the table and Render. 

The process instance is rendered as shown in the image below.