From the Harry Potter series, what is the symbolism of Harry's scar?
One possible interpretation of Harry's scar is that it is a physical reminder of his infant resistance to Lord Voldemort. While no adult wizard had the magical power to resist Voldemort, Harry's innate gifts were enough to save him from a death curse; the price for resistance was the scar, which also acted as a mental link between them. This shows the balance between good and evil, specifically the intentional, deliberate evil of Voldemort, and the infant Harry, who as an infant was entirely innocent.
Another major symbolism is the link between Harry and his parents. Although he never knew them, he finds that their love for him was the most important aspect of their lives. Part of the reason he survived was due to their love, which was in direct opposition to Voldemort's evil. Dumbledore comments:
"He didn't realize that love as powerful as your mother's for you leaves its own mark. Not a scar, no visible sign... to have been loved so deeply... will give us some protection forever. It is in your very skin."
(Rowling, Harry Potter and the Sorcerer's Stone, Google Books)
The love that protected him had no physical sign; the protection itself, the power of parental love, conflicted with the killing curse and so marked Harry for life. In the end, the scar reminds Harry of his parents, of the sacrifices that others made for him, and that he cannot shirk his destiny for selfish reasons.
Later in the series, the scar also becomes to symbolize the piece of Voldemort's soul that resides in Harry. The scar begins to pain him whenever Voldemort utilizes that connection to share memories and peer into Harry's mind. The fact the scar doesn't hurt him after he kills Voldemort also reinforces this symbolism.