The object is to have a hand with a total value higher than the dealer's without going over 21. Kings, Queens, Jacks and Tens are worth a value of 10. An Ace has the value of 1 or 11. The remaining cards are counted at face value.
Yes, there is usually a betting limit at a blackjack table, which is set by the casino. The limit can vary depending on the casino and the specific table. Casinos typically have both minimum and maximum betting limits to ensure that they can manage their risk and maintain the integrity of the game.