The first thing you should know about communications is,
90% of a project manager’s job is communication
It also makes for a nifty little exam question. To start off with the basics, communication is a two way process of transferring information. The next thing you should know is the communication model.

You begin the process of communication by encoding your message into something as simple as an email. The call travels through a medium or channel for instance the internet. The team receives the mail and decodes it to understand what you are trying to say. If there was an interference along the way, let’s say an attachment gets corrupted, it is call noise. This entire cycle is the communication model.
The whole idea behind managing communications (or communications management) is to ensure that everybody gets the right message at the right time. There are three processes in this knowledge area,

Plan Communications Management
The process of determining the information needs of stakeholders by developing an appropriate approach and plan for project communication with the available organizational assets and the needs of the project. This is basically the content of the Communication Management Plan
Manage Communications
The process of ensuring timely collection, creation, distribution, storage, retrieval, management, monitoring and the ultimate disposition of project related information. This is done in accordance to the communications management plan
Monitor Communications
The process of ensuring the information needs of the project stakeholders are met. This process was known as Control Communications in the pre-PMBOK 6 world.
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