It is hard to write a book that is entirely mythical and contains assumptions from the worlds of wizards and witches. They need to be suspense-filled, mysterious and full of fantasy.
The formula of books
JK Rowling's work can be defined as a formula where she introduces a lot of interesting artefacts and creatures with some mischief and dreadful Bosses. Harry Potter's world revolves around a school of magic known as Hogwarts. Things like Quidditch, the magical wand and the Nimbus Two thousand brings a lot of attention to her books.
But only a little introduction is not enough to bring a lot of readers. Rowling's works put a lot of details into everything to bring it to as much realism as possible. For example, the initial information about how different wizards reacted when the word Voldemort was spoken in front of them. The introductory books tell how Harry Potter unknowingly won the battle against the furious dark lord when he was an infant. His lightning mark on the forehead made him very famous across the wizarding society. However, he was treated like a slave in the Muggles family. In the battle, he lost his father and mother, and no one knows how. (No Spoilers!!)
Basic introduction
The novels usually start with Harry living with the muggles; then someone takes him away from their poor behaviour. Many people have varied views on the Houses Gryffindor, Ravenclaw, Hufflepuff and Slytherin. Some think that Gryffindor should have remained in the last while the members tried to understand why their points were deducted.
Each novel chronicle one year in Harry's life at the school of Hogwarts. The Books also contain many flashbacks frequently experienced by Harry. During the starting of the Philosopher's stone book. The wizarding society has gone through a terrible event and was very happy that the you-know-who died and everyone was happy because of Harry Potter. They celebrated at such a large scale that even the muggle word started to notice signs of the world of magic. The owls were soaring all over the sky.
Despite everyone's effort to hide Harry's glorious future in the muggle world. It still showed signs now and then. The Dursley's were terrified of the boy and just wanted to keep him as a slave and waste his incredible potential.
In Layman's terms, JK Rowling books are worth a read in one's lifetime.