A medium is a person who provides evidence and can validate that life continues after the physical body is shed. The evidence is provided by physical description, the circumstance in which the person has passed, age of passing, personality traits, specific place/events that took place when they where in the physical form. After this information is validated the medium delivers the message from spirit.
A psychic reading offers guidance concerning life issues weather it is relationships, business, employment, ect. and what is going on past, present of the future.