In the Book
In the Movie
Bilbo is more than fifty years old.
Martin Freeman, who portrays Bilbo, doesn't look that old at all.
Thorin arrives at Bilbo's along with three other dwarves.
He is the last to arrive and is alone. He comes after they have started eating.
Bilbo tries to sneak out of his home to avoid going on the adventure.
He doesn't attempt to leave.
Bilbo's mother was rumored to be part Fairy. His mother's influence is what gave him his interest in adventure.
This is not explained.
Radagast the Brown is mentioned in passing as one of the five wizards living in Middle Earth. He doesn't take part in the story.
He is in the film. He interacts with Gandalf, the dwarves and Bilbo throughout.