Sleight of hand, also known as 'prestidigitation' ("quick fingers") or léger de main (from the French for "lightness of hand"), is the set of techniques used in magic (or gambling) to manipulate objects commonly cards and coins secretly.

Advanced sleight of hand requires months or years of practice before it can be performed proficiently in front of spectators. Sleight of hand is mostly employed in close-up magic for best effect.

The idea of Mentalism varies greatly from place to place but in the proverbial nutshell it can be described as Parapsychological activities, such as telepathy and mind reading and is something that is said to be employed by psychics and clairvoyants the world over; Whether you believe in this ability or not is your choice.

What I practice is suggestion and giving the illusion of a "sixth sense" through observation and deductive reasoning. 

 

Suggestion is the name given to the psychological process by which one person may guide the thoughts, feelings or behaviour of another. Advertising is a classic example.

for example if I said DO NOT think of a pink elephant; you can not help think about it because the command is there and it will probably stay there for a while.

Its the same as when you were younger walking on a wall or up high somewhere and your Mother says nay shouts  "do not walk up there or you will fall!" all of a sudden you get shaky and topple because your mother gave the embedded command "you will fall!"  in her order.

If you know of suggestion it need not be so obvious and the more proficient you become the more subtle the influences can be.