Cards are flat, rectangular pieces of paper or plastic that often feature images, text, or symbols. They are commonly used for various purposes, including playing games, sending messages, or making transactions. Playing cards, for example, are used in games like poker and bridge, while greeting cards are sent to celebrate occasions like birthdays or holidays. In addition to recreational uses, cards also serve practical functions. Credit cards and debit cards allow individuals to make purchases without cash, while business cards provide contact information for networking. Overall, cards are versatile tools that play significant roles in both entertainment and everyday life.