It is a cards game. In which two players(here the user and computer which takes random cards) will playing and the sum of the cards number will be calculated and if one of them have lower sum then he/she can take the card and add the number to their sum. But if any player has higher the number, max at 21, then that player wins the game. if any player got 21 exact then it will immediately wins the game and they got BLACKJACK! But if any player got the number higher then the 21 it immediately lose the game and opposite player wins.
All the cards have the numbers but queen, king, jack has 10 numbers and A has 11 instead of 1.