What is a big blind and a small blind in poker and explain what they are and do?

The blinds are forced bets in Texas Hold'em and Omaha. The reason for blinds is that both of these games do not have an ante and the players could fold their hands without an investment in the game. The big blind is equal to the minimum bet and the small blind is half the big blind. The small blind is directly left of the dealer button and the big blind is directly left of the small blind. Once the initial hand has been dealt the player left of the big blind then has the opportunity to call, raise, or fold. Basically, the whole concept of blinds is to entice players to stay in the game and add to the pot.