Narratology is the study of how we make or 'construct' narratives.
A readable summary that I've found useful is this one:
Shlomith Rimmon-Kenan, Shlomith Narrative Fiction : Contemporary Poetics
The core idea behind all this is that when we tell or write a story, there is a kind of core, original story behind the one we are telling which we might call the 'plot'. Then, there's what we do with the plot - which is tell it, (i.e. 'the story'). I can write the story using hundreds of different ways e.g. first person narrator, third person. Or I might use flash-backs or flash-forwards, dialogue or no-dialogue, sub-plots, plots within plots and so on.
I might also switch 'point of view' - this is sometimes called 'focalisation' and the person through whom I 'see' what's going on at a particular moment in the story is called the 'focaliser'. In some stories we know several points of view, in some only one. In some stories, we know a lot about what people think, in others (folk tales, for example), hardly anything.
Another point of variation in written prose stories is how it is I get to know what's going on inside someone's head. Novelists in particular have devised many different ways of doing this - now all classified by narratologists. It's fun to see, for example, how 'free indirect discourse' was invented and has been used by writers ever since.
Here's an essay on how Jane Austen used several systems of letting us know what a character thought but also put opinion (whose?) into the voice of the omniscient narrator:
Behind all this lies the question of 'textualisation'. That's to say, we have to remind ourselves that nothing in a text is 'real'. Though we talk in shorthand about 'characters doing' things, or having this or that motive, in a sense this is nonsense: these are all within language, described by language and at that particular moment, by the language of the text we are reading. (Theatre, film, illustrated books, comics, graphic novels and live-story-telling also involve 'mimesis' - pictorial representations, acting out of actions so involve other features other than language - of course!)
This idea of textualisation led to the notion that a text has an 'implied author'. If we think of all writing as a form of ventriloquism, then we can see that the author is the ventriloquist but there are moments when the dummy 'speaks'. The ventriloquist can make the dummy say anything and maintain the pretence that it is not the ventriloquist him- or herself doing it. Now, if we look at what the dummy is 'saying' - this will express a point of view, ideas, thoughts. They may or may not be the point of view or outlook of the ventriloquist. We do not know if they are. The notion of the 'implied author' enables us to separate the text from the author, just as I am doing here with ventriloquist and dummy.
Again, in shorthand, it is very easy to say that the author or writer 'says' this or that in a work of fiction...but actually writing is an act of ventriloquism. It is a textualised viewpoint - or indeed with a novel - many viewpoints. We may then suggest that there are views ('ideologies') implied by such a text - perhaps in the outcome of what happens to the various characters when faced with dilemmas and problems - but we don't know for certain that this is the author's view. Indeed, the author may not know either!
It may be possible - and this is commonplace - to establish across several books and by positioning a writer in time and place and history - that there are views that appear to represent a pattern and an overall ideology. Even so, look how hard that proves to be when talking about Shakespeare.
This throws us back to readers. There is no one single idealised 'reader'.
This is the central fallacy of most school-based criticism. Students and children are asked to 'Explain the description of...' or 'Show how the first lines of the poem are effective...' and so on. Hiding behind these phrases is the idea that there is a single 'idealised' reader who responds to the text in the way that the examiner says the reader should. This reader will supposedly find that particular use of language 'effective', or that those particular words do have that 'effect' on all readers and so on.
Some will want to say that there are 'common readings' or that there are 'communities of readers' for whom there are common responses, so a short cut to saying it's 'effective' is a way of saying that this is the 'generally agreed' response. My own view of that is that when it comes from the authority of exam boards, this is nothing more than imposing the view of the 'academy' or establishment. I agree that there are ways in which readers' responses cluster and clump together according to the sociology of readers but also that 'resistant reading' is always possible. Or indeed, contradictory reading is always possible. And that we might change our views over time as we go through life and changes in our life.
This is particularly apparent when it comes to children's books. A book we read when we are 11 may well have different significances when we read it when we are 35. The book didn't change, we did and the times we live in change too.
This then leads to another concept - the 'implied reader'! Can we say by looking at a text that it implies a certain kind of reader? If I write, 'Little Diddykins went up to his Mummy and said, 'Mummy, can I have drink?"' can we deduce that this is a text intended for a certain kind of reader? Is the reader 'inscribed' on the text, in the text? Is this reader the 'implied reader'? (Beware the possibilities of irony and parody though. What may appear to be being implied (!) may in fact be simply some kind of mockery and that behind the parody or irony lies another 'implied reader' who spots the irony or enjoys the joke.)
Some texts (like the one you're reading here) implies a certain kind of interest and level of education, perhaps? You are implied by the text before you even started reading it.
But do texts have the power, through this kind of inscribing, to imply a certain way of reading? If I write a first person narrative which calls on you to identify with the 'I' narrator, is this somehow 'less sophisticated' than an omniscient narrator who take us around several characters and expresses many different view points? Do these different methods of narration 'position' the reader and in a sense fix the reader in some way to a certain kind of world outlook? This is the viewpoint of John Stephens in 'Language and Ideology in Children's Fiction'. Perhaps this takes too much away from the autonomy of the reader for my liking...and takes us back to this idealised single 'reader'. Even so, it's a challenging read. It's the only book I know which looks closely at the ideology of narration in children's books. (Maybe it was the first and I haven't kept up with the latest!)