Point of View
If you Google Point of View hundreds of links turn up and most books about creative writing have chapters on it. I don't plan to cover every nuance but it is something that I spent a lot of time thinking about when I did my MA.
First person is told by a narrator who describes the action as thought they were explaining it to another person. Imagine describing your first day at school. I think everyone (anyone) reading this is likely to be old enough that their first day at school is a distant memory. It might run something like this
I walked thought the gate and was frightened out of my mind by all the yelling kids. The only door I knew, the one to Mrs Robert class, seemed miles away. I'd been here last week but I came with my mum in the middle of the morning when the playground was empty. Now there were more kids than I could count, all bigger than me, milling around between mum, back at the gate and the only door I knew. As I stepped forward there was a girl my size a few yards ahead, taking steps as small as mine, clutching her coat around her, as though she was trying to be invisible. I knew at once that if I could get to her side we both might make it. That's how I met Susan.
In first person stories the narrator has access to their own thoughts but not to those of anyone else. In the above example the narrator recognises that Susan may also be frightened of her first day at school, because she has the same hunched walk. There are any number of signs to observe, body language, eye contact, tone of voice, gestures and so on. If the writing is to feel authentic it must not describe other people's thoughts because apart from a few telepaths and mind readers none of us know for sure what other people are thinking.
It is possible to write in first person omniscient point of view but to work the story has to be told by a character who could reasonably be expected to know what others are thinking. There are examples but the narrators are usually ghosts or gods. For example; "The Lovely Bones"— told by a ghost. "The Book thief"— told by death "Galapagos"— Told by a ghost.
I used this POV in my MA thesis where there were two narrators, a ghost and the studio building in which much of the story took place.
Second Person is an uncommon POV but can work very effectively for some sorts of stories.
You walked through the school gates and as soon as you saw the crowd of children you stopped and seemed to shrink for a moment. You half turned as if to look back and then set your shoulders and kept going.
In this POV the narrator does not see into any internal dialogue, everything is told by an external narrator. To some extent, as a consequence it can sound boring because the reader has to rely on the second hand observations of a faceless narrator.
If you imagine yourself as a movie director telling actors what to do it is possible to get some idea of how it can work. For example:-
As the shot opens the camera will catch you in profile, wit two seconds and then turn towards the camera and in another beat you smile, recognising Susan.
Third person is probably the most flexible POV for a number of reasons.
The narrator can describe any scene involving any characters. That makes it more flexible because the story can spread over a variety of scenes in which some but not all of the characters are present. In a first person narrative it is difficult to include events in which the narrator is not involved. It's not impossible but it can be difficult. In a third person narrative that problem does not arise.
Perhaps because third person is so flexible some conventions have arisen as much to help readers as writers. There are said to be three (or possibly four) types of third person voice: Omniscient, Objective and Limited.
The most flexible POV is third person omniscient. In effect told by a camera in the sky; by God, or at least an author behaving as if he or she had god like powers. As few of us have much experience at playing God it is said to be more difficult for the reader to instinctively feel the voice as authentic.
Why this should be is hard to determine because not long ago this was a voice used by many successful authors. All those Arthur Ransome books I read as a kid were in a third person omniscient voice. The narrator sees inside the heads of all the characters including the dog.
Third Person Objective is when the facts of a narrative are reported by a seemingly neutral, impersonal observer or recorder. In other words the reader is given relatively bald facts from which they must draw their own conclusions.
Third person limited is different because whilst the facts may be just as baldly stated the narrator also allows us to see inside the head of one of the characters. The insight into the character (often the hero) is treated the same way as in a first person narrative but in addition the third person narrator can give us an external view of the character at the same time.
I say there may be a fourth third person POV because it is possible to mix things up a little.
If we think of the narration as if coming from a camera we then have to think about where the camera is placed. Is it a head camera glued to one character's forehead? Or maybe on their shoulder like an outside broadcast mobile camera, or is it a fixed camera on a tripod or moving platform. Does it have one lens or can it switch to telephoto or close up. What about a camera on a boom. Do any of these machines have zoom lenses.
A film director knows when to switch from long lens to close up, when to fade, when to jump cut. Equivalent techniques can be used in writing.
The fairly solid convention with third person limited voices is that the narrator only reveals the internal voice of one character. Some writers mess with this, changing the close character in different chapters or even within the same chapter. There is a convention that when switching within a chapter it is only fair to the reader to give them a clue — this is usually done with a wider space between paragraphs and some marker like a short row of stars or a dotted line.
I have written one story where I used an internal voice for two characters, a husband and wife because I thought it would give the reader a view of the closeness of their relationship. It also gave me the possibility of making the POV more limited when they had a row.
Conventions exist because they have been found to work. There are writers who break the rules, sometimes very successfully, but they do run the risk of committing two mortal sins; either confusing the reader, or looking amateur.
EXERCISE
Imagine one person giving something to another person. It can be anything from an apple to a poisoned chalice, whatever suits your imagination.
Write it in each POV. First person, second person, third person omniscient and third person limited.
Without telling the reader the story behind the action or the motive of either party, try to show that by the way that the action is described.