POKER BLINDS & ANTES
Before cards are even dealt in a game of holdem, it is important to have some initial money in the pot. Otherwise every player could just wait for aces in the pocket before making any investment. It would also make pot limit games a little difficult to get going. The two ways to start this are antes and blinds and we'll go into each in detail.
Antes are a set amount put in the pot by every player in the game prior to cards being dealt. This amount does not count toward your bet on the first round of betting, unlike blinds. This simple method is used primarily in home games. This method also is not very common with texas hold em specifically, it's more often found in games like five-card stud or draw. Antes are also used in conjunction with blinds in the later stages of a tournament.
Based on the limit of the game, the player to the left of the dealer's button (the small blind) and the player two to the left of the button (the big blind) are required to put up mandatory bets before the cards are dealt. These blinds count toward your total investment toward the first round of betting. So if the pot isn't raised pre-flop, the small blind will only have to put in another half a bet to call. Likewise, the big blind won't have to put anything more in the pot, although the big will have the ability to raise his own blind. In an unraised pre-flop pot, this is referred to as the "option".
The amount that is put out depends on the limit. In fixed limit poker, the big blind puts up a bet equal to the small limit. The small blind puts up half that amount. So if the limit is $5/$10, the big blind is $5 and the small blind is $2.50. This is not like a no limit or pot limit poker game. In a $5/$10 no limit hold'em game, the small blind would be $5 and the big blind would be $10.
Blinds and Antes in Tournaments
The way holdem tournaments are structured, the blind and/or antes go up after a set period of time, called the "escalation". Each group of time where the blind/antes stay the same is called a "level". Usually when players go up a level, the blinds double or less. If antes are introduced, they usually do not double every level.
Sometimes to start a tournament, the big and small blind are the same amount and at the next level the big doubles.