Dialogue is about exploring a problem from all possible perspectives. During dialogue, everyone suspends their own beliefs, and there’s a shared search for the truth.
Discussion is defending your own point of view and looking for the best point view to support a decision that must be made.
Both dialogue and discussion are needed in a healthy team, but people often only engage in discussion.
…in discussion different views are presented and defended and there is a search for the best view to support decisions that must be made at this time.
— The Fifth Discipline