As Scout grows older, she also grows wiser, and she comes to recognize that Boo Radley is not the raw squirrel-eating ghoul that legend dictates. Without ever laying eyes on Boo, she comes to recognize that he is a kind soul, and by the end of the novel, she sees that he is also the heroic protector of both of the Finch children. Beginning with the gifts left in the knothole of the tree--the gum, the knife, the lucky penny and the carved figurines--Scout slowly comes to recognize that Boo wants to be their friend. It's still a scary thought to her, however, but two more acts of kindness help to sway her way of thinking. First, Jem finds his pants unexpectedly folded and mended hanging on the Radley fence. Jem and Scout realize that only Boo could have done it. Later, on the night that Miss Maudie's house burns, Scout discovers a blanket wrapped around her shoulders. Atticus joking explains that the whole town must have been out to watch the fire--even Boo, who placed the blanket around Scout for warmth on a cold night. By the night of the Halloween carnival, Scout had already come to the conclusion that Boo was a friendly but eccentric loner who preferred life locked away in his mysterious house. After Boo came to the children's rescue after being attacked by Bob Ewell, Scout recognized him as "our neighbor," a protector and a friend.

At the beginning of the book, Boo Radley is not a human being to her.  He is some sort of weird monster.  She and Jem are deathly afraid of him yet they also use him for their own fun.  In other words, they really don't see him as a person like them.

At the end of the book, Scout has learned that you have to be more understanding and respectful of all sorts of people.  by Chapter 29, she is able to say "Hey" to Boo like a real person.  By Chapter 31, she walks home with him and cares enough to make sure that it looks like he is escorting her so that other people will respect him.

Over the course of the book, Boo Radley becomes a real person to Scout.

In the beginning of the novel, Scout's narration explains that Boo was "a malevolent phantom." They had never seen him, but they believed the stories (most of them, anyway) they had heard: that he killed cats, ate squirrels, poisoned pecans, and peeped in windows. They believed Boo would kill them if he got the chance.

"... he'll kill us each and every one, Dill Harris," said Jem.

Dill's curiosity drove Jem and Scout toward the goal of making Boo come out. They were still afraid of him until the presents in the knothole began to appear. After eliminating all other possibilities, the children unspokenly agreed that Boo was the giver of the gifts. Miss Maudie assured them that most of the rumors about Boo were untrue and that they

"... were three-fourths colored folks and one-fourth Stephanie Crawford."

Jem's and Scout's goals changed once again, especially after Scout thought she heard laughter coming from the Radley house. They wanted to communicate with Boo--actually see him and talk with him, and their fear began to fade. The clincher came when Jem went back to retrieve his lost pants, only to find them folded and mended, waiting for him on the fence. On the night Miss Maudie's house burned down, the mysterious blanket that Scout found on her shoulders came from Boo, Atticus explained. By then, the knothole had already been sealed, and the children began to believe that they would never see Boo Radley.

Dill later tells us that he feels sorry for Boo and understands why he stays inside his house.

"... it's because he wants to stay inside."

By the night of the fateful Halloween attack, the children have little fear of passing the Radley house. They certainly didn't fear an attack from Boo, but attacks from others had not entered their minds. When Scout sees Boo standing in Jem's room following the news of Bob Ewell's death, she realizes that it was Boo who had saved them. "Mr. Arthur" immediately went from unseen phantom to a real-life hero, and she only wished that Jem could have been awake to see Boo for himself.