JSON-LD is primarily used to represent linked data on the web. It’s used to represent data from social networks, like Twitter or Facebook, and data from RDF database dumps.
JSON-LD can also be used to represent linked data in other formats, such as RDF/XML or Turtle. JSON-LD is an ideal format; it is easy to read and write and supports all the Linked Data principles.
JSON-LD has several features that make it great for linked data. For example, support for multiple typed values and directed graphs.