Psychic mediumship is the practice where a medium acts as a bridge to communicate with spirits of the deceased, receiving messages through heightened psychic senses like clairvoyance (seeing), clairaudience (hearing), and clairsentience (feeling) to offer evidence that life continues after death, differing from a regular psychic who reads about the living. Mediums tune into spirit energy, translating personal details from spirits to validate their presence for clients (sitters).