Vanishing points, commonly applies to artworks..
It is usually used in composing a landscape, cityscape to duplicate realism. You can pick the the vanishing point in your artwork, either left, center or right of your horizon, this will guide you to apply your elements in your artwork by using this vanishing poits as starting point of your perspective.
As for real life photograpy, try taking picture of your neighborhood, it is difficult to determine the vanishing point. It depends on who is looking at the picture or which subject or element in the picture the one who is looking prefers to establish his/her own vanishing point.
