What is a decentralized COIN?

Could you elaborate on the concept of a decentralized coin? I'm curious to understand how it differs from traditional, centralized currencies. Specifically, what are the key characteristics that define a decentralized coin? Does it rely on blockchain technology? How does the lack of a central authority impact its operation and security? Also, are there any advantages or disadvantages to using decentralized coins compared to traditional currencies? I'd appreciate a concise yet comprehensive explanation of this emerging financial concept.