Token is an unofficial term for most uncollectible minions that are summoned directly into play by other cards. Those cards may include minions with triggered effects or Battlecries such as Violet Teacher and Cenarius, or spells such as Imp-losion and Force of Nature. They are usually weak in statistics with simple or no special abilities. Some "families" of tokens exist, with similar or identical names, statistics and ties to classes, particularly Warlock Imps and Druid Treants.
The term "token" originally comes from Magic: The Gathering, in which physical tokens are used to represent creatures that are not represented by cards, but are created by other cards. For this reason, "token" is generally used in collectible card games as a term for small generated creatures.
Where the definition of "token" ends is a gray area. Minions summoned in multiples or by a variety of sources are clear examples; in contrast minions only created once by a single collectible card are often excluded. Those may be categorized under other names, such as Gelbin Mekkatorque's "inventions" and Animal Companion's "beast companions". Copies of collectible minions and cards generated into the hand are almost never included. These distinctions may be due to the strategies typically associated with use of tokens, which rely on having a number of expendable minions in play.