What defines a wiki in terms of communication?

A wiki is defined primarily as a collection of articles that users can edit collaboratively. This open editing feature is the hallmark of wikis, allowing multiple users to contribute, modify, and update content in real-time. This collaborative nature makes wikis particularly effective for knowledge sharing, documentation, and community-based information gathering, as users can build upon each other's contributions to create a comprehensive resource.

Wikis thrive on user participation and the idea of collective intelligence, enabling a dynamic form of communication where information can be updated or refined continuously. This differs significantly from the other options, which do not encapsulate the core functionality of a wiki. For instance, live video discussions focus mainly on real-time interaction without the collaborative editing aspect; a private journal restricts access to authors only and does not facilitate broader communication; and a management tool for company policies may govern specific internal guidelines without the collaborative, open nature of a wiki. Thus, the defining characteristic of a wiki lies in its collaborative and editable collection of articles.