Type (biology)
The International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN) make rules for type specimens.  In these rules, the scientific name of every taxon is almost always based on just one specimen. Types are usually specimens that are kept in a museum or herbarium research collection.  These types are usually whole organisms in a preservative, for example alcohol. Sometimes they are just pictures of the organisms. Describing species and appointing type specimens is part of scientific nomenclature and alpha taxonomy.