There are normally two betting structures that you can play, either
limit or no-limit poker.
In a fixed limit game, a player chooses only
whether to bet or not - the amount is fixed by rule. Usually later betting
rounds specify higher bets than earlier rounds. E.g. a four-round game called "1 and 2 limit" (usually shown as $2/$4)
may state that bets on the first two rounds are $1, and on the next two rounds $2.
This amount applies to each raise, not the total amount bet in
a round, so a player may bet $1, be raised $1, and re-raise another $1,
for a total of $3.
A poker game played with a no limit structure enables players to raise any
amount of their stake at any time (according to the table stakes and raising rules).
With either betting structure there is first a forced bet known as a blind. With texas
holdem this is generally the first 2 players to the dealers left, known as a
small blind and a big blind. The actual value depends on if limit or
no-limit poker is being played. With limit poker the small blind is usually
equal to half of a small bet, and the big blind is equal to a full small bet.
With no limit poker, the blinds normally starts at a low value then increases
during the game at a fixed time.