Each Suit contains 14 cards. Similar to a regular deck of cards, they have an ace, 2 to 10 numbered, queen, king. They also contain the page and knight which split the spot the Jack would typically occupy. These cards were originally used to play certain card games and still are throughout many European countries. The Suit of Swords would correspond with the Spades suit. However, they can be used for divination, which has become increasingly popular in The United States.
In tarot, Swords represent the Air and refer to knowledge and power. These are associated with the balance between good and evil. Swords can also sometimes be thought to speak to healing and cleansing energy. It is a masculine energy indicate of virility and strength.
Should a reading be primarily Swords, you may be in desperate need of some self-reflecting.