Hocruxes are dark magical objects in the Harry Potter series created by the dark wizard Lord Voldemort. They are formed by splitting one's soul and hiding a fragment within an object, allowing the creator to attain immortality as long as the Hocruxes remain intact. To create a Hocrux, a person must commit murder, which splits the soul. Each Hocrux serves as a safeguard for the creator's life, making them difficult to kill. The destruction of a Hocrux requires specific methods, such as using Basilisk venom or Fiendfyre, which can obliterate the object and the soul fragment within it.