Generally, roleplaying (also abbreviated to RP) is the act of assuming personalities for different characters or situations, in order to give the game a more realistic atmosphere. For instance, a character can play the role of a dwarf, and start talking and acting like one. Roleplaying is art itself. It's attempting to write a book in real time. As in a book, roleplaying is not only based on talking, but also on personalities, actions, drama, protagonists and antagonists, and much more. Resuming, roleplaying is creating in details a whole new scenery where a story is taking place, and then proceeding with that story.
From the slightest will to provide an "escape" from reality, to the will to make all your Dolera adventures more exciting, roleplaying can really become a pleasant activity. Afteralls, you can do almost anything you want, perform every personality you feel like, and also join this huge medieval atmosphere that makes our creativity flow like never before. But we should never let roleplay become a reason for disagreements and fights, as roleplaying is a way of relaxing and enjoying the unlimited universe a single game makes us feel in.