Fungibility vs Lightning Network

Fungibility means each unit of a currency or asset is interchangeable with any other unit of equal value, with no unit being worth more or less than another due to individual characteristics, history, or origin—a critical property for money to function effectively.

Lightning Network is Bitcoin's primary Layer 2 scaling solution that enables instant, low-cost payments through off-chain payment channels, processing thousands of transactions per second while inheriting Bitcoin's security by periodically settling on the Bitcoin blockchain.