Velvet RiverPreflop
The first betting round, after hole cards are dealt and before the flop.
Preflop action starts with the player to the left of the big blind, a seat called under the gun. Each player can fold, call the big blind, or raise. The big blind acts last and may check if nobody has raised.
Most of the money a beginner loses goes in preflop with weak starting hands. Tightening up preflop is the fastest improvement available to a new player.
Example
Blinds are $1/$2. Under the gun raises to $6, everyone folds to the button, who calls.