Are used to store and transport data. Many open data standards are expressed in one or more of the following:

• JSON - a lightweight data-exchange and file format easily understood by computers and humans.
• JSON-LD - Linked Data (LD). enabling a network of standards-based, machine-readable data across the web.
• RDF-Resource Description Framework which includes a subject, object, and their relationship. Each piece has a URL. RDF is commonly expressed in Turtle format (compact, stackable, human-friendly) and can be expressed (serialized) in JSON-LD, among other formats.
• OWL-Web Ontology Language, a complex language for taxonomies/classifications built on RDF.
• XML - Extensible Markup Language, a language and file format similar to HTML that describes data with tags that the developer defines.
• SKOS - Simple Knowledge Organization System, built on RDF/RDFS.
• YAML - Yet Another Markup Language, which can parse other formats into a human-friendlier layout.
• EDI-based standards - Electronic Data Interchange (EDI), a format to transport business documents between organizations and across industries.
• CSV-Comma-separate Values, a text file that has a specific format that allows data to be saved in a table structured format.