A private policy is a legal document which defines that how an organization is going to gather, uses, discloses and manages the data of its client. Most of the websites make their own privacy policies which are generally available/visible on its website. This document also states whether the personal data of the customers will be kept confidential or not. Personal data may include name, address, date of birth, contact number, etc.
To read more about privacy policies, follow this link: http://en.wikipedia.org/wiki/Privacy_policy