After the preflop stage comes The Flop. All the betting from the preflop has finished and the dealer will now turn over three cards face up and side by side in the middle of the table. These cards are called the flop (as in the image above).
There will eventually be five cards face up and side by side in the middle of the table, there are known as the community cards. But for now the dealer just lays down three. After the cards have been placed on the table another round of betting will take place.
Starting from the player still in the hand who is closest to the left of the dealer and working around the table in a clockwise direction each player can now choose to bet, check, raise or fold. Note that if no bet has been placed before a player can check meaning they wish to stay in the hand but not place any bets, if a player after them bets they will have to choose to call, raise or fold when play comes back to them.
If you’re playing no-limit Texas Hold’em the bet amount must be equal to or greater than the big blind. In limit Hold’em, the best must be exactly the amount of the big blind.
Once this round of betting is complete (everyone has put the same amount into the pot or folded) then we move on to the next stage of the game. The next stage is called, Then Turn and you can see the rules to the turn by clicking the previous link.