Text box handles manipulate the origin or the size of the text box while maintaining the relationship between origin and justification.
Handles on text boxes appear as an X square, a hollow square, or a solid square.
An X handle indicates the origin of the text box. Selecting an X handle modifies the origin.
If you select a hollow handle, you move the text box; therefore, you are moving the origin of the text box.
You select a solid handle to modify the text box along at least one axis. You do not modify the origin.