Collectible cards, such as trading cards, are valued for their rarity, condition, historical significance, and artistic design. Popular types include sports cards (e.g., baseball, basketball), gaming cards (e.g., Pokémon, Magic: The Gathering), and entertainment cards (e.g., Star Wars, Marvel). Factors affecting their value include rarity, condition (graded by services like PSA and Beckett), popularity of the featured character or player, and demand among collectors. Professional grading services provide a standardized assessment of a card's condition, significantly impacting its market value.