# The development finance ontology

The development finance ontology is the DFO's model of the development finance domain. It defines concepts in development finance and how they relate to each other, forming the layer that defines what each DFO figure means.

Development finance data comes from a variety of publishers, such as the OECD, IMF, World Bank, and UN agencies. They often use different names, codes, and categories for the same concept, and draw on different code lists and classifications, such as the Creditor Reporting System (CRS) code lists or the System of National Accounts. The DFO ontology is a unified model of development finance that brings together the classifications used in these datasets.

The ontology lets you:

- Compare figures that measure the same thing, whichever publisher reported them.
- Look up the written definition of each concept used to describe a figure.
- Trace a figure back to the category its publisher used, since each publisher's own categories are kept as published alongside the shared concepts.
- Ask in your own words. Each concept records the other names people use for it and how it relates to other concepts, so the DFO's search and AI assistant can match the words in your question to the right concepts, even when you don't use the publisher's terms.

## How the ontology is built

The ONE Data team builds and maintains the DFO ontology, drawing on international statistical standards, publishers' official code lists, and domain expertise. Each concept has an official label, a definition, its other names, the codes publishers use for it where they have one, and its relationships to other concepts. It builds on schema.org and the Data Commons schema, reusing concepts that fit and adding new concepts of development finance.

The DFO ontology is publicly accessible at [developmentfinance.wikibase.cloud](https://developmentfinance.wikibase.cloud/wiki/Main_Page), built with Wikibase.