Its main purpose is to reduce the effort for users trying to express their formatting directly as valid HTML markup.
The Shield UI Editor widget allows you to tailor it fully - implementing custom commands, flexible API and events for manipulating its content, tools for Selection and Range, etc.
The component can also be used to edit tags, different than TEXTAREA, in place. In inline mode the editor toolbar if floating next to the editable element and can be dragged to a more convenient position with the mouse.
As with any other ShieldUI widget, the Editor control comes with a set of predefined themes, which ensure consistent look across products. You can also come up with new themes, to handle any specific visual requirements.