The answers are: It is led in a methodical and procedural way. It uses specialized, subject-specific language. It requires preparation in the form of research or review.
Any formal discussion, like the one you could find in an academic conference, will always aim to be highly structured so that the arguments presented will reflect a methodical arrangement in their delivery, which is important in order to avoid ambiguity or miscomprehension.
Also, formal discussions would have to employ a specialized and subject-specific language in order to express, as accurately as possible, the meaning of the information conveyed that is particular to a single subject matter.
Finally, to expose the previous traits, there is no doubt a high expectation to prepare for the discussion by doing profound research or reviewing the topic extensively so as to be able to handle and manage all the nuances of a formal discussion given on a specific and specialized topic.
