The Text Box tool places a text box on top of the page content and unlike the Sticky Note (which can be opened and closed) it is always visible. Text Boxes can blend into the page content, so if you don’t want them to be missed, it’s worth making sure the color of the text box is different to the content on the page.
Tip: When trying to edit the properties of a text box, you need to be aware that there are different states, and you can only open the Properties dialog from one state. When the cursor is flashing inside the text box, you must click outside of the text box and then right-click to bring up the menu that gives you access to the properties.