After a brief pause where Dumbledore showed his first sign of alarm during the duel, Voldemort attempted to possess Harry, in the hopes that Dumbledore would sacrifice his pupil to kill the Dark Lord. However, the power of Harry's love made it impossible for him to possess Harry for long and he was forcibly ejected.

Is Voldemort inside of Harry?

A horcrux is a part of a person's soul that has been separated and placed in an object. In the movies, we first hear about them in The Half-Blood Prince (2009) when Horace Slughorn explains the magic to Harry. ... TL;DR: The piece of Voldemort's soul inside of Harry used its magic to protect him from harm.

Who did Lord Voldemort possess?

Quirinus Quirrell served as a temporary Horcrux when Voldemort's soul possessed his body in 1991. However, the piece of the soul survived Quirrell's demise, and was destroyed six years later when Voldemort was killed.