An information security policy is a document that defines the rules and guidelines for protecting the confidentiality, integrity, and availability of data and systems in an organization. It covers topics such as data classification, access control, encryption, backup, incident response, and compliance. An information security policy is essential for ensuring that data is shared securely with external parties, especially when using SaaS fileshares that may have different security standards and features than the organization's own systems. A communication policy, a resource management policy, and an identity control policy are all related to information security, but they are not as comprehensive and specific as an information security policy.