If something is viewpoint-neutral, it does not speak in favor of just one point of view. A viewpoint-neutral book, for example, aims to deal with facts. When mentioning opinions not based on fact, it remains impartial, presenting all sides of the argument fairly, without declaring any right or wrong.
To present a neutral point of view, a publication provides references and sources, which act as evidence for the facts presented. A reference indicates where readers may find the information for themselves.
Scholars in every field of study try to be viewpoint-neutral, instead of only presenting things that fit their own views. Media such as newspapers and television documentaries aspire to the same objectivity. On the Web, the user-created encyclopedia Wikipedia has an NPOV policy whereby it expects all contributors to demonstrate a neutral point of view.