It is hard to classify Harry Potter and the Prisoner of Azkaban as a book or a film. The movie is more like a story that we know from the books. In fact, it is hard to distinguish from the first one or the second one. If you like reading, you might also want to read this one as it is a continuation of the series.
The series was so popular that Warner Brothers had to create a spin-off movie trilogy. The first one starts with the release of Harry Potter and the Chamber of Secrets. It takes place in the third year of school. It's during this period that the characters find the secret of the Philosopher's Stone. During the second part of the series, Harry is forced to hide his identity and learn the dangers of being a wizard from a former enemy of the Dark Lord.
You can always read the books from the series. It is always recommended to start from the beginning. But if you are not interested in reading the books, you can watch the movies instead. This will give you a better perspective of the books and it is also more interesting if you watch the movies with a friend.
If you do not like watching the movies, you can always download them from the internet. This is because movies are much better than books. They are entertaining, easy to follow and they don't have a narration like the books. If you really enjoy watching the movies, you can also watch them online.
The first part of the Prisoner of Azkaban is full of surprises. The plot is easy to follow and it gives the readers a good view of the world of Hogwarts. Even the story ends at the end of each chapter. The plot is very well done.
The second part of the series is better than the first. It is also more realistic. The focus of the books is not that easy to understand. For example, when the Dark Lord is about to use the sword of Slytherin on Harry Potter, a seventh-year student, he tells him, "The end justifies the means."
The movie takes it to another level. It includes the whole education process and the hardships that students go through. It will also show the enemies of the Dark Lord and the connections between them. The two plots merge together and it will be difficult to distinguish which one is the first part and which one is the second part. The movie will also show how Harry Potter, Hermione Granger and Ron Weasley will be able to defeat the enemy and overcome their differences.
If you are still confused about which part of the series you should read, just read the first or the second part of the series. As long as you read the first part, you can always start reading the second one as well. It is best to start from the beginning and you can choose which part to read.