It's a way of communicating your business concept to outside parties -- the reason it needs to contain only nonconfidential information.
You see them often in the energy and hi-tech sectors. They tend to include an executive summary, a short statement of the opportunity being offered, an overview of the business and business model and, depending on your audience, an outline of terms and conditions and disclaimers.
Knowing what to divulge and what to keep close to the vest should not be a decision you make with your gut. You'd want to avoid intimate details about intellectual property or trade secret business processes in a non-confidential overview.
It's a good idea to consult with professional advisors so that you don't give away too much information or use wording that can cause you to run afoul of state and federal securities law and Federal Trade Commission regulations.
Definitely don't pull one off the Internet and copy it.