Definition of heads up
Heads-up translates to "head-to-head". In poker rooms, you will find several types of poker tables; full ring (FR, with 8, 9 or 10 players) shorthanded (SH, with 4-5 or 6 players) and heads-up (HU, with 2 players). In cash games, any table that has only two seats is called a heads-up table. This is the most dynamic type of game there is. You will have to play more than half of your starting hands, which is not usual for shorthanded or full ring players. Heads-up poker can be the most profitable poker game there is if you are good at it.
Heads up in tournaments
There are also heads-up tournaments. These tournaments are shootouts. Once you have beaten an opponent, you are paired with another opponent, until only one player remains, the winner of the tournament. This is also known as heads-up play in sit'n'gos and tournaments. When there are only two players left in a tournament or sit'n'go, the tournament is called heads-up. This is an intense moment in the tournament because the first place payout in tournaments is often much bigger than the second place payout.