What exactly is a non-disclosure is terms of business deals and transactions?

Question

I was told that I am going to need a company(ies) I am speaking to about setting up a website to sign a non-disclosure. Information about unpatented business ideas will be shared and my impression of the disclosure is that it gives me protection without the need of a patent. Is that what a non-disclosure is? And how does it work? What else does a non-disclosure protect me from in this case?

Answer 1

A non-disclosure agreement states that the parties specified in the document agree not to "disclose" (or tell anybody about) the subject of the agreement.  

Without a non-disclosure agreement, others that you share your ideas with could steal them and claim them as their own, or simply blab to your competitors about your plans.

Answer 2

It protects the company and holds you liable for disclosing any proprietary information you gain from working inside the company.