Notes

Text and commentary: text boxes, marks on the sheet's own text, callouts, sticky notes, stamps and signatures.

Notes tools put words on the sheet, or mark words the sheet already has. Nothing here is measured and nothing here is traced: where Draw and Shapes mark where, these mark what about it.

Three of them work on the document's own text rather than on the page as a canvas, and those only do anything on a sheet that has a text layer to select. The rest place something new: a box you type into, a leader with a label on the end, a folded note, a stamp, a signature.