Texas hold'em is the most popular kind of the old and famous poker game. Currently Texas hold'em is the major and vastly played poker game online and in all casinos and card clubs in many countries. Several players sit at a table. Two cards are dealt face down to each player (starting hand). Then the dealer, first opens three cards (flop cards), next he opens one card (turn card), and last he opens one more card (river card). These five cards are the "community cards." Players use one or more of their cards, in conjunction with one or more of the five community cards to make the best hand to win the hand. The game has several stages. There are folding, betting, calling, raising, and re-raising between the stages of the hand. All monies are piled in center of the table (pot). During each hand, when a player makes a bet that no one calls, or at the end, whoever has the best hand wins the pot. In Texas hold'em the three cards of the flop are very important. These are 60% of the five community cards. Flop cards are the base and foundation of most of the hands that are made in this game. By observing these cards the players would know: 1) what hands they've already made or will make soon, 2) what hands their opponents may already have or will make soon. Flop cards come in many different rank and suit combinations. For better understanding of the flop cards, the three cards of all flops were classified into seven types. Flop type 1 has one, flop types 2 and 3 each have two, and flop types 4, 5, 6, and 7, each have three variations. Practical frequency of occurrence of the 7 flop types was surveyed and the results are discussed. For recognizing the flop types and their variations a quiz is given. Many aspects of each of the 7 flop types and their variations are extensively discussed. For example, hand making possibilities under all flop types, what players learn from each flop type, which flop types are safe or dangerous, what are the visible and invisible danger signs in each flop type, etc. along with the use of many tables are explained. In short, in the long run, flop type knowledge helps players to be more successful in the game of Texas hold'em.