Too Long; Didn't Read
Swarm is based on [libp2p](https://hackernoon.com/writing-decentralized-applications-in-script) (underlay network), but nodes are addressed by its Ethereum address (overlay network) Swarm uses the DHT (DHT) as a database where peers can find where the data is stored. Swarm splits it into 4K chunks and stored on nodes that are the nearest to the chunk address. Every chunk is stored redundantly on the 4 nearest nodes. Swarm calls this solution DISC which means Distributed Immutable Store for Chunks.