When we talk about Point of View (POV) in writing, we're mean the narrative perspective from which the story is told.
In 'The First Five Pages: A Writer''s Guide to Staying Out of the Rejection Pile,' Noah Lukeman says 'Viewpoint and narration compromise a delicate, elaborate façade, in which one tiny break or inconsistency can be disastrous, the equivalent of striking a dissonant chord in the midst of a harmonious musical performance'.
So basically, decide on your POV and stick to it!
David Lodge, in 'The Art of Fiction’ goes further when he says the point of view is arguably, 'the most important single decision the novelist has to make, for it fundamentally affect the way the readers will respond.'
How are you going to decide?
The book 'On Editing’ by Helen Corner-Bryant and Kathryn Price says 'The point of view you choose can have a big impact on everything in your story – from its mood and atmosphere through to the way the reader perceives and interprets your characters'.
So what's the point of POV?
Most of us have, at some time, refereed a childhood squabble where everyone passionately believes their own truth:
Abigail is sure Bobby kicked the ball in her face on purpose (because he was scowling at her when he started to run at the ball).
Bobby insists he was concentrating on the goal and was distracted by the crazy dog who jumped at him and made his kick go askew.
If you write the story from Abigail's point of view it will be very different from Bobby's.
And the dog may have yet another version of the course of events.
You need to know which perspective you want your reader to see and that will dictate your choice of POV.