The labels are used loosely
In everyday deal practice, NDA and confidentiality agreement are often used interchangeably. Some advisers use NDA for a short, simple document and confidentiality agreement for a longer one with more detailed obligations. Others use whichever term their firm's template happens to carry. You will also see one-way documents, where only one side is sharing, called confidentiality undertakings or letters.
Because the names overlap so much, the title tells you very little. What matters is what the document actually says: who is bound, what information is covered, what the recipient may do with it, and for how long. Two documents with the same title can say very different things, and two with different titles can be almost identical.