Cold Reading
A "cold reader" is a kind of fortune teller who does not use devices like cards, palms, or stars, but instead has a conversation with you, and then tells you things about yourself that you had no idea how they knew. More importantly, they may give you information about yourself that you had not known but recognize as true. Cold reading has interested persons who otherwise pay no attention to fortune telling. While part of it is trickery, it also uses skillful understanding and observation of people. For more information, see this Wikipedia article, or Cold Reader Tips by MasterClass.