What are the three different types of point of view and when are they used in To Kill a Mockingbird?

Scout is the narrator in this novel, but when she is
telling the story, she is grown up. So the point of view is interesting - it is that of
an adult trying to relate her thoughts as a child. In this sense, the reader really has
two points of view - the one of Scout as a child, and the one of the grown-up Scout, who
is relating what she remembers when she was a child. The adult narrator, however, has
learned many things, so even though she is telling the story through flashbacks, readers
are privy to her thoughts through an adult filter.

Another
point of view in the novel is that of Jem. The narrator Scout devotes a great deal of
time to describing things through Jem's point of view when they were children. This is
because Jem was her beloved older brother who in spite of the typical sibling stuff,
loved and protected his younger sister, Scout. Scout loves Jem very much, and this comes
out in the novel. It also gives the readers another view of things as Jem was an older
child and understood some things that the childhood Scout did not understand at the
time.