A Mentalist is someone who uses their mind to do cool things and impress people. They can read people's thoughts, predict the future, and do other mind-boggling tricks. They are like magicians, but instead of using fancy props or illusions, they rely on their keen observation skills, body language reading, and hypnosis techniques to create an illusion of having mental powers.
For example, they may ask you to think of a number between 1 and 10 and then guess the number you're thinking of. They may also ask you to choose a card from a deck and then somehow magically know the card you picked. It's not magic, but a combination of psychology, entertainment, and showmanship.
A Mentalist uses techniques like cold reading, hot reading, and suggestion to create the illusion of knowing things that they couldn't possibly know. A cold reading is when they use vague statements that can apply to almost anyone to make it seem like they know things about you. A hot reading is when they do some research on you beforehand and use that information to make it seem like they're reading your mind.
Overall, a Mentalist is a performer who creates a fascinating and entertaining experience for people by playing with their minds and making them believe in the impossible.