1. Foreign exchange market - Wikipedia

    https://en.wikipedia.org/wiki/Foreign_exchange_market

    The foreign exchange market (Forex, FX, or currency market) is a global decentralized or over-the-counter (OTC) market for the trading of currencies.

  2. Local exchange trading system - Wikipedia

    https://en.wikipedia.org/wiki/Local_exchange_trading_system

    A local exchange trading system (also local employment and trading system or local energy transfer system; abbreviated LETS) is a locally initiated, democratically ...