I'm reading a novel called Persepolis for my English course, and it's about a girl named Marji that grows up during the 1979 Revolution. The author's intention with the novel is to break Western stereotypes of Iran and to show what it was like growing up during that time period. Marji is a fictional character, but she is supposed to represent the younger version of the author (Marjane Satrapi), who actually lived in Iran during the revolution. What would this technique of representing yourself as a character be called? I found out through Google that it's called "self-insertion", but I don't know if that's right because the whole book revolves around Marji.
There are several related terms and it's not clear what applies without knowing the novel. There's a difference between representing your life story and representing your opinions.
An autobiographical novel (Wikipedia) is a fictionalised version of an author's life, possibly with names and other details changed. A semi-autobiographical novel is similar, but more heavily fictionalised (probably with incidents that never happened but generally approximating reality). Autobiographical fiction is a similar term for works in genres other than the novel.
Autofiction is another term for blending autobiography and fiction; according to Wikipedia it typically refers to more experimental writing and is generally written in the third person while an autobiographical novel is in the first person. (There are other similar terms too, but a lot are the invention of a small number of writers.)
Self-insertion would refer to inserting yourself in a larger narrative; the other terms above generally refer to a narrative centred on the author-character. Similar to this an author surrogate is a character based on the author, who doesn't necessarily live out the author's actual life or experiences, but is used to express the author's point of view. A difference is that self-insertion is often more pejorative, often referring to an idealised version of the author (sometimes called a Mary Sue), and it is often associated with fan fiction. (Wikipedia's article on self-insertion is short but refers to an "idealized character" who represents the author.) I don't think either author surrogate or self-insertion is the best term here.
It's simply called the Author's Alter Ego - the alternative me.
It can be a character inspired in the writer with add-ons, generally positive traits. Or simply can be a fanciful character which the writer desires to be
Most of the time such operation suffers from a psychological limit: you portray yourself not exactly how you are but pretty generally as how you would like to be seen by others. It's somehow a mark for the posterity, or at least what you would like people in general would talk of you.
Such choices are generally driven by inner needs most of them developed yet on childhood. Not trustable at all.