Hey good question. You’re probably looking at a bilateral NDA, which is when both parties supplies information that is supposed to remain a secret. These agreements are common for businesses that are considering a merger of some sort. Many attorneys advise on a mutual NDA in all cases in order to draft the provisions to be fair and equal for both sides in the event that the information receiving party later becomes a disclosing party.
On the other hand, a unilateral NDA is basically when one party would like to disclose certain information to another party and wants to make sure the other party does not take and use the disclosed information.
If you’re looking for lawyers with experience drafting NDAs then feel free to check out.