Whitelisting is a security practice that allows only approved entities to access a system or network. This means that only specific users, applications, or IP addresses can interact with the system, reducing the risk of unauthorized access and potential threats. By maintaining a list of trusted sources, organizations can better protect their sensitive information. In the context of software, whitelisting can prevent harmful programs from running on a device. For example, if a company uses a whitelist of approved applications, only those on the list can be installed or executed. This helps ensure that only safe and verified software is used within the organization.