Digital Signatures in Acrobat
A true digital signature "digitally ensures" the authenticity of the person(s) signing a PDF. Acrobat can create and authenticate true "digital signatures."
However, it should be emphasized—truly emphasized—that 99 percent of the time the simple signature stamp will suffice.
In fact, if you try to use a true digital signature in situations where the recipient isn’t versed in using them, quite often, your signature will be questioned and possibly rejected. So the best way to "digitally sign" is usually by using a signature stamp