"Need-to-know basis" is a principle that restricts access to confidential or sensitive information only to individuals who have a legitimate and essential reason to know it. In other words, it means that information is shared only with those who require it to perform their job duties or fulfill a specific purpose. This principle is often used in situations where confidentiality and security are of the utmost importance, such as in government agencies, military operations, or corporate organizations dealing with sensitive information. The need-to-know basis ensures that information is protected from unauthorized access or disclosure, and it minimizes the risk of information leakage or misuse. For example, in a military operation, soldiers are given information that is relevant to their specific mission and nothing more. Similarly, in a corporate organization, employees are given access only to the information they need to perform their job, and no more. This helps to maintain a level of security and confidentiality that is necessary for the success of the operation or the organization.

When information is only available to people who have a specific reason to know about it. Ex. If a large truck full of gold was going to come through town. Only some police who were involved in guarding it are told of its route.