Paper cards are small, flat pieces of paper or cardstock that often serve various purposes, such as greeting cards, business cards, or playing cards. They can be printed with images, text, or designs and are typically used for communication, marketing, or entertainment. These cards come in various sizes and shapes, depending on their intended use. For example, business cards are usually rectangular and contain contact information, while greeting cards can be folded and feature messages for special occasions. Playing cards are often used in games and come in a standard deck format.