I am halfway through the book: The Global Negotiator where the author speaks about communication categories based upon purpose. 

These are:

  1. Phatic: This type of communication consists of the preliminary discussions that are intended to build a binding personal relationship. It helps in creating a personal bond before coming to the negotiation table.
  2. Informational: The sharing of information is the most obvious purpose of communication. 
  3. Persuasive: This type of communication happens when one person desires to persuade another. 
  4. Cathartic: The purpose of this type of communication is the release of emotions. The need to share emotions with another person relates to both positive and negative emotions.