IPFS enables the creation of completely distributed applications.
Inter-Planetary File System aims to make the web faster, safer, and more open.
Inter-Planetary File System is a Distributed Ledger Technology
A file is a Merkle DAG out of the data in the files you specify.
Inter-Planetary File System follows the unixfs data format when doing this. This means that your files are broken down into Block, and then arranged in a tree-like structure using 'link nodes' to tie them together. A given file's 'hash' is actually the hash of the root (uppermost) node in the Merkle DAG. For a given Merkle DAG, you can easily view the sub-blocks under it with ipfs ls.