Tarot is both an individual and a team game. During the game, one of the players, called the attacker (or taker) is opposed to the other players, the defenders, who constitute a team (the Defense). But this association only lasts for the duration of one round 😉.
After seeing their hand, each player can commit to reaching a certain number of points by playing alone against their opponents. It's called the Contract. When you declare a contract, you are making the "bet" to cumulate a certain number of points. You become the Attacker.
Your objective is to win the most hands by playing the highest value cards possible, therefore scoring more points than the opponents, to reach your contract. After each round, a points count is made and determines if the contract is successfully made or failed.
To find out what the different contracts are and how to choose the one that will guarantee your success, let's read the following FAQ: Card values, points, and contracts.