GBIF now deals with four types of biodiversity data:
- Occurrences (observations, specimens etc)
- Sample-based data (ecological monitoring and assessment data)
- Checklists (names)
- Metadata (data about data)
Occurrences are records that document a 'collection event'—evidence that a particular, named organism was found at a particular time and place. Also known as primary biodiversity data, occurrences document the 'what, where, when, how and by whom' of our exploration of the planet's species. An occurrence record can be based on an observation in the field, vouchered (labelled) specimen in a museum or herbarium, or other evidence.
Sample-based data are records from thousands of different kinds of environmental, ecological, and natural resource monitoring and assessment investigations. These events range from one-off surveys to ongoing monitoring and includes activities like freshwater and marine sampling, plant cover and vegetation plots, and citizen science bird counts, among others.
Checklists are lists of scientific names of organisms grouped into taxonomic hierarchies. They serve two main functions: first, they provide data that help to enrich information about particular species, for example by including them on national checklists, and on lists of invasive or threatened species; and they provide taxonomic 'backbones' around which species information can be organized.
Metadata are structured descriptions of datasets giving essential details such as the geographic and taxonomic scope of the data, methods of collection or observation, contact details and citation requirements. They help to give context to datasets and enable users to assess whether data are fit for use in a particular research project or application.