What is the dark coin?

Excuse me, could you elaborate on what exactly the "dark coin" is? I've heard the term mentioned in the context of cryptocurrency, but I'm not entirely sure of its specific nature or purpose. Is it a type of digital currency designed for anonymous transactions, similar to Monero or Zcash? Or is it something entirely different? I'm curious to know more about its features, how it operates, and what sets it apart from other cryptocurrencies in the market.