You can tell a story from one person’s point of view (third person limited), which means that the reader comes to know that character very well, or you can tell a story from several or multiple points of view. Each has benefits and drawbacks. If you tell the story from a single point of view the advantage is that the reader begins to identify closely with that character and will follow the character. This point of view can also limit the reader, but not necessarily: think again to Hilary Mantel’s Wolf Hall, in which the story is told from Cromwell’s point of view but more. Through Cromwell we come to know many characters in depth not because Cromwell tells the reader, but because of his interactions and dialogue with other characters. The effect is to make the reader think he’s reading a novel from multiple points of view. This is a coup of craft, the feat of a master novelist.
If you use multiple points of view, you can deepen a story, and if you overlap points of view, you can enhance the drama. This requires development of a unique voice for each character (which is not your voice). This allows the author to layer the story and allows the reader to view the story from different angles, but you also risk losing the reader because you scatter her attention instead of focusing it on one person. And the goal is always to use point of view to bring the reader into the story.
Third person point of view expands story