What chain is RVN on?

Could you please elaborate on the blockchain network that RVN, commonly known as Ravencoin, operates on? I'm curious to know the specific technical details behind its infrastructure. Is it a fork of an existing blockchain, or is it a completely new and independent implementation? Understanding the underlying technology of RVN's blockchain is crucial for investors and enthusiasts alike, so I'd appreciate a concise yet comprehensive description of its network architecture.