Baseball cards are collectible trading cards featuring professional baseball players. Each card typically includes a player's name, team, position, and statistics, along with a photograph. They are often produced by companies like Topps and Upper Deck, and can vary in rarity and value based on factors such as the player's popularity and the card's condition. Collectors often seek out specific cards to complete their collections, and some cards can be worth significant amounts of money. The hobby of collecting baseball cards has been popular since the late 19th century and continues to attract enthusiasts of all ages today.