Explanation:

According to the PMBOKGuide, effective communication requires the project manager to recognize and manage the different dimensions of communication to ensure the right information reaches the right person.
* Formal Communication: This involves structured and documented information. It is essential for maintaining the project ' s " official record. "
* Focus: Reports, meeting agendas, and minutes. These are formal artifacts that may be used for audits or legal documentation.
* Internal Communication: This refers to communication within the project and the performing organization.
* Focus: Project stakeholders. While customers are stakeholders, in this specific categorization, " Internal " refers to the team, senior management, and functional departments within the company.
* Informal Communication: This involves less structured, daily interactions that help build relationships and solve minor issues quickly.
* Focus: General communications activities using email. While email can be formal, general daily emails, ad-hoc conversations, and social media activities are classified as informal dimensions.
* External Communication: This refers to communication with entities outside the performing organization.
* Focus: Customers and vendors. Since these parties are outside the legal boundary of the company, communication with them often requires specific protocols (contracts, formal statements, or specialized account management).
* Internal vs. External: The key differentiator is the organizational boundary. Employees and internal managers are internal; anyone else (contractors, government regulators, clients) is external.
* Formal vs. Informal: The key differentiator is the level of structure and permanence. If it belongs in the project archives as a record of a decision, it is formal. If it is a tool for coordination and team bonding, it is likely informal.