A communications plan, in project management, is a policy-driven approach to providing stakeholders with information about a project. The plan formally defines who should be given specific information, when that information should be delivered and what communication channels will be used to deliver the information.
An effective communications management plan anticipates what information will need to be communicated to specific audience segments. The plan should also address who has the authority to communicate confidential or sensitive information and how information should be disseminated (email, web sites, printed reports, and/or presentations). Finally, the plan should define what communication channels stakeholders should use to provide feedback and how communication documentation will be archived as part of the project records.
In some organizations the communications management plan may also include a glossary of common project terminology that will be used within the project. This glossary may define and include samples of templates, reports and forms that the project manager will use to communicate information.
This video from the Project Management Channel explains how to set up a simple communication plan.