What is IPFS
IPFS is a decentralized file storage system, where IPFS acronym stands for Interplanetary File System.
For those familiar with other distributed file systems, such for example as HDFS (Hadoop File System), IPFS has a lot of similarities in its design and functioning to other distributed file systems. It operates a network of nodes where the same file / blob can be stored in multiple copies, with no central server, therefore providing higher availability and lower risk of data loss.
IPFS is often used in blockchain / DLT projects where there is a necessity to store large binary files. Blockchain transactions can only store a small amount of data (typically equal to a string) so in cases where a binary object needs to be referred or included into a transaction, such transaction can include a hash or an URL linking to a larger object stored externally.
Such external storage can be centralized (think AWS S3, your own web hosting etc), or decentralized. IPFS offers the latter option for such use cases and is often used in blockchain projects.