Canasta is a classic card game that originated in Uruguay in the 1940s and gained widespread popularity in the 1950s.
 Here are the basic rules:
Players: Canasta can be played by 2 to 6 players. It's usually played with four players in partnerships.
Deck: Canasta is typically played with two standard decks of 52 cards (104 cards total), plus four jokers, making a total of 108 cards.
Objective: The main objective of Canasta is to score points by forming melds of seven or more cards of the same rank, and to "go out" (play all of your cards).
Setup:
Each player draws a card from the shuffled deck. The player who draws the highest card becomes the dealer.
The dealer shuffles the cards and the player to their right cuts the deck.
The dealer deals 11 cards to each player if there are 4 or more players. For 2 or 3 players, 15 cards are dealt to each player.
The remaining cards form the draw pile, with the top card turned face up to start the discard pile.
Gameplay:
Players take turns in clockwise order.
On a player's turn, they draw two cards: either two from the draw pile or one from the draw pile and one from the discard pile.
After drawing, players may form melds by laying down sets of three or more cards of the same rank. A meld must contain at least three natural (non-wild) cards and can contain wild cards (jokers or deuces). A meld of seven or more cards is called a "canasta".
Players may also add cards to existing melds on the table, including melds made by their partner.
At the end of their turn, players discard one card onto the discard pile.
The round continues until a player "goes out" by playing all cards in their hand or until the draw pile is depleted.
Scoring:
Points are scored for melds and canastas, as well as for going out and other bonuses.
Red threes, if held in a player's hand at the end of the round, count against the team's score.
The round ends when a player goes out or when the draw pile is empty. Players then tally their scores, and the next round begins.
Ending the Game:
The game typically ends when a player or team reaches a predetermined score, often 5,000 points.
The player or team with the highest score at the end of the game wins.
These are the basic rules of Canasta, but there are variations and additional rules that players may choose to incorporate for added complexity or enjoyment.