The parties of the NDA. There are two parties - Disclosing Party and the Receiving Party.
The Disclosing Party is the one that discloses the information that should be kept secret (the business)
The Receiving Party is the one that receives the information and should keep it secret (the employee/contractor).
The dates. The NDA has a beginning and end date.
The NDA starts applying on the beginning date. From that date, the Receiving Party must not disclose the information.
The end date is the date from which the NDA does not apply and the information can be disclosed freely.
If there is no end date, the NDA applies indefinitely and the information must not be disclosed at any time. This can be changed only by an annexe to the NDA signed by both parties.
The information. The information to be kept secret is an essential part of the NDA. For better protection, describe it precisely.
The information could be presented as a list (this is recommended) or as a narrative.
It doesn’t matter how it is described, as long as both parties are clear with expectations.
Exclusions of the NDA. It describes in what situations the receiving party may use confidential information.
Return of information. When the contract ends, the receiving party should return the information to the disclosing party. It may mean the return of documents, USB drives, etc.
Governing law. If the parties have a dispute, it will be resolved according to the governing law chosen by them.