There are various styles of communication, with assertive communication being the most effective as it clearly expresses thoughts and feelings openly and honestly. The document discusses five main communication styles - assertive, aggressive, passive-aggressive, submissive, and manipulative. It also examines models for categorizing communication styles using two dimensions: expressiveness and assertiveness. These categories include systematic, direct, spirited, and considerate styles. Each style is then defined in terms of its characteristics and approach to expressiveness and assertiveness.