Elizabeth Bennet can be seen as the figure of "prejudice" described in the novel's title. The first time she meets Mr. Darcy, she overhears him saying that she, Elizabeth, is not pretty enough for him to ask her to dance. She laughs it off to her friends, but she develops a deep prejudice against him. She thinks he is an arrogant, hateful jerk.
Like most people who develop a strong opinion, Elizabeth looks for confirmation of it. She finds all she wants in the handsome Wickham, who tells her stories of having been wronged and cheated by Darcy. Elizabeth believes them—without seeking any confirmation—because they fit her preconceived notions of who Darcy is.
At the end of the novel, Elizabeth is a more mature person who has learned to see through her prejudice. She falls in love with Darcy and realizes she was wrong to so hastily jump to judgment based on one stray remark.
Her changed point of view, however, doesn't just happen. Austen paints a realistic portrait of a young woman who starts out opinionated and impulsive, sure that her opinions are right. For example, it never occurs to her that Charlotte might have a good reason to marry Mr. Collins. Over time, and after experiencing that there are other sides to stories, Elizabeth develops into a more nuanced woman, and she is capable of loving Darcy despite his flaws because she can see there is more to him than his pride. Darcy, too, changes, getting over some of his own pride and arrogance because of his encounters with Elizabeth.