Someone who is didactic tells people things rather than letting them find things out or discussing things. He is more didactic in his approach to the learning process
Something that is didactic is intended to teach people something, especially a moral lesson. In totalitarian societies, art exists for didactic purposes
(from the Greek didaktikos, meaning 'apt at teaching') Something which is intended to instruct Didactic conveyed a neutral meaning when it was first borrowed in the 17th century, but now often has negative connotations, because something didactic can be overburdened with instruction to the point of being dull, or it might be pompously instructive or moralistic