In poker, we call the blind when forced bets are made before any distribution of cards. It is therefore a ‘blind pot”, hence its name.
The presence of two blinds is currently the most widespread, the small and big blind, the second being at least equal to twice the former. For example, some may have blinds of $1 and $2, or $10 and $25. The big blind is the minimum value of a bet.
The use of blinds ensures the circulation of money between players and allows a first selection at the first round of betting. Thus, no player can go to out without losing or winning money.
In general, during a tournament, the blinds increase steadily with the elimination of players, not to decrease the proportion of the blinds relative to average chips (which increase as eliminations).
The two players who put the blinds are also the last two to act, and have the advantage that they already know what their opponents have done, and can use this information to make a decision.
When a poker game is played one against one, it is the donor who makes the small blind and the other puts the big blind. This is to avoid that the donor is first to bet at all turns. The dealer bet first in the first round of betting (pre-flop) then this is his opponent in the next rounds.