A psychic medium is also different from a psychic reader. A reader uses their extrasensory perception to acquire information from metaphysical energy. This form of metaphysical practice for people who do this type of energy work requires the most interpretation from the practitioner.
A psychic medium is able to communicate very directly with metaphysical entities. Although there is some interpretation involved, it is significantly less.
Those entities could be your Guides. They could be your Guardians They could be your Angels. They could also be loved ones that have passed (including animals).
However, they can also communicate with people who are very much alive. This is because a psychic medium is communicating Spirit to Spirit. Depending on the skill set of the practitioner, a psychic medium may be able to communicate with an individual in a coma or living with dementia in ways that the general public cannot.