Key differences between the movie and the book?I mean differences like background, characters etc any visual or information provided.

The differences between a book and a movie take place for
many different reasons. Whereas a book must describe everything in detail so that the
reader can imagine it, the movie has the benefit of video to show in a flash what a book
may take several paragraphs or pages to show.

Many people
are disappointed because the characters in the movie do not look like those the reader
has imagined. Also, some movies are not true to the book and may change the color or
ethnicity of a character. It may be fine for those only watching the movie but it
typically annoys the person that has also read the
book.

The hardest thing to translate is a
person’s thoughts or motives. Thoughts cannot be shown on the silver screen. The
director must turn those thoughts into action including tone and inflection of the voice
as well as facial expressions.

In more “literary” works the
person that writes the screenplay must drastically reduce scenes, characters and
settings that are not germane to the overall story. While this may change the direction
of the story it is often seen as being a necessary
evil.

Those that think they can just watch the movie
instead of reading the book are typically going to be in hot water as the two are rarely
the same.