Some PDFs are forms you can fill out and then print or send. (PDF forms that aren’t editable won’t allow you to select or enter text.) If a form requires a signature, you can add your signature to the PDF.
Fill out a PDF form
Open Preview on your Mac and open the PDF form
Click the Show Form Filling Toolbar button
Click a field in the form and type your text
If you save the form (by choosing File > Export), you can close it, open it later, and continue to fill it out.