Velvet RiverAnte
A small forced bet that every player (or just the big blind) posts before a hand, on top of the blinds.
Antes appear mostly in the later levels of tournaments. They grow the starting pot, which makes stealing the blinds more profitable and pushes players to play more hands.
Most modern tournaments use a "big blind ante", where the big blind pays the whole table's ante in one amount. It speeds up the game.