IPFS

IPFS (InterPlanetary File System) is a decentralized filesystem. IPFS uses DHT (distributed hash table) and Merkle DAG (directed acyclic graph) data structures. It uses a protocol similar to BitTorrent to decide how to move data around the network. One of the advanced features of IPFS is that it supports file versioning. To achieve file versioning, it uses data structures similar to Git.

Although it called a decentralized filesystem, it doesn't adhere to a major property of a filesystem; that is, when we store something in a filesystem, it is guaranteed to be there until deleted. But IPFS doesn't work that way. Every node doesn't hold all files; it stores the files it needs. Therefore, if a file is less popular, then obviously many nodes won't have it; therefore, there is a huge chance of the file disappearing from the network. Due to this, many people prefer to call IPFS a decentralized peer-to-peer file-sharing application. Or else, you can think of IPFS as BitTorrent, which is completely decentralized; that is, it doesn't have a tracker and has some advanced features.