Collaborative writing is writing done by more than one person; they may discuss what they are going to write before they start, and discuss what they have written after they finish each draft they write.
协同写作是指由多个人完成写作；他们可能在开始之前先讨论他们要写什么，在每个人完成了自己部分的草案之后再讨论他们写了什么。