Artist trading cards (or ATCs) are miniature works of art about the same size as modern baseball cards, or 2 ½ X 3 ½ inches (63 mm X 89 mm), small enough to fit inside standard card-collector pockets, sleeves or sheets. The ATC movement developed out of the mail art movement and has its origins in Switzerland. Cards are produced in various media, including dry media (pencils, pens, markers, etc.), wet media (watercolor, acrylic paints, etc.), paper media (in the form of collage, papercuts, found objects, etc.) or even metals or cloth. The cards are usually traded or exchanged. When sold, they are usually referred to as art card editions and originals (ACEOs).

M. Vänçi Stirnemann is credited in many circles with popularizing the modern artist trading card in 1996, holding trading sessions in Zurich, Switzerland. This resurgence of interest of Artists trading cards has spawned the popular ACEO (art card editions and originals) movement.

An offshoot of artist trading cards are art card editions and originals (ACEOs), which originated when some artists began to create cards to sell, in addition to trading among themselves. Many ACEOs are sold on internet auction sites, such as eBay. As the term suggests, ACEOs may be small original works of art, or editions of small prints.

A trading card (or collectible card) is a small card, usually made out of paperboard or thick paper, which usually contains an image of a certain person, place or thing (fictional or real) and a short description of the picture, along with other text (attacks, statistics, or trivia). There is a wide variation of different types of cards. Modern cards even go as far as to include swatches of game worn memorabilia, autographs, and even DNA Hair Samples of their subjects. as to the configuration of objects, the content on the card, and even the material used to make the card.

Trading cards are traditionally associated with sports; baseball cards are especially well-known. Cards dealing with other subjects are often considered a separate category from sports cards, known as non-sports trading cards. These often feature cartoons, comic book characters, television series and film stills. In the 1990s, cards designed specifically for playing games became popular enough to develop into a distinct category, collectible card games. These tend to use either fantasy subjects or sports as the basis for game play.