# Data reference

Activities, products, flows, quantities, geographies, system models and formats.

- [Unit processes, LCI and LCIA](/en/data-reference/unit-processes-lci-lcia) — Unit processes, cumulative inventories and impact assessment results.
- [Activities and reference products](/en/data-reference/activities-and-reference-products) — Identifiers for activities, datasets and reference products.
- [Elementary and intermediate flows](/en/data-reference/elementary-and-intermediate-flows) — Flow types and public flow catalogs.
- [Reference quantities and units](/en/data-reference/reference-quantities-and-units) — Reference product quantities, flow units and category indicator units.
- [Geographic fields](/en/data-reference/geographies) — Geographic identifiers, codes, names and recorded parents.
- [System model definitions](/en/data-reference/system-models) — Definitions of the available system models.
- [Data formats](/en/data-reference/data-formats) — Public catalog files and data formats.
- [Glossary](/en/data-reference/glossary) — Standard LCA terms and fields used on this site.