Palming

The art of card palming can be brought to a degree of perfection that borders on the wonderful. It is very simple to place one or several cards in the palm and conceal them by partly closing and turning the palm downward, or inward; but it is entirely another matter to palm them from the deck in such a manner that the most critical observer would not even suspect, let alone detect, the action.
The main purpose of palming the card is to steal one or more cards from the deck for later use, cheater could hand mucking (switching) the card to get a better hand. They can steal cards while they are: hanging out the deck to be cut or shuffled, cutting the deck and even shuffling the deck.

Switching

Some cheats specialize in switching cards. Sometimes one card (or more) can be switched within the cheat's hand for a more desirable one, thus improving the cheat's hand and bettering the odds at winning the pot. At times even the entire deck can be switched for a new deck. In this case the new deck can be switched for a marked one or one whose order of cards has been prearranged to favor the cheat(s). The main advantage that card switching offers is that the cheating can be done on another player's deal.
There are two main types of switching cards, the first one is called "the hand mucking" and the second one is called "the cooler move".

Hand mucking: Hand mucking is a term describing any of the sleight of hand techniques used to switch one or several cards in one's hand. A cheat who specializes in hand mucking is called a "hand mucker". Several techniques of mucking exist - each being adapted to a particular game.

Cooler move: A "cold deck" or a "cooler" is a deck, which is "cold" (so to speak) because it has been secretly switched in, so it has not yet been "warmed up" by the player's hands. The "cooler move" is any of various sleight-of-hand techniques used to switch in a cooler.