Swarm is a development stack that is a native base layer service of the Ethereum web3 stack. Swarm is a development platform that allows developers to build content distribution and distributed file storage decentralized applications (dApps). Swarm allows users to efficiently pool their bandwidth and storage capabilities to run services created using Swarm and Ethereum. Swarm is integrated with the Ethereum devp2p multiprotocol network layer and with Ethereum blockchain solutions for domain name resolution, service payments, and content availability insurance.
Announcing Swarm Proof-of-Concept Release 3
Decentralized Storage and Publication with IPFS and Swarm -- SitePoint
Setting up a multi node private ethereum swarm network without a blockchain