$ETH coin, a piece of metal or, rarely, some other material (such as leather or porcelain) certified by a mark or marks upon it as being of a specific intrinsic or exchange value.

The use of cast-metal pieces as a medium of exchange is very ancient and probably developed out of the use in commerce of ordinary ingots of bronze and other metals that possessed an intrinsic value. Until the development of bills of exchange in medieval Europe and paper currency in medieval China, metal coins were the only such medium. Despite their diminished use in most commercial transactions, coins are still indispensable to modern economies; in fact, their importance is growing as the result of the widespread use of coin-operated