IPLD allows us to treat all hash-linked data structures as subsets of a unified information space.
IPLD stands for InterPlanetary Linked Data and ‘is a single namespace for all hash-inspired protocols. Through IPLD, links can be traversed across protocols, allowing you to explore data regardless of the underlying protocol.’
From https://ipld.io/
See IPFS is a peer-to-peer hypermedia protocol, Linked Data, Solid – Social Linked Data
References
Very good docs: https://ipld.io/docs/