information:classification
Modern

For at least 1,000 years the name Celt was not used at all, and nobody called themselves Celts or Celtic, until from about 1700, after the word 'Celtic' was rediscovered in classical texts, it was applied for the first time to the distinctive culture, history, traditions, language of the modern Celtic nations – Ireland, Scotland, Wales, Cornwall, Brittany, and the Isle of Man. 'Celt' is a modern English word, first attested in 1707 in the writing of Edward Lhuyd, whose work, along with that of other late 17th-century scholars, brought academic attention to the languages and history of the early Celtic inhabitants of Great Britain. The English words Gaul, Gauls (pl.) and Gaulish (first recorded in the 16–17th centuries) come from French Gaule and Gaulois, a borrowing from Frankish * Walholant, "Roman land" (see Gaul: Name), the root of which is Proto-Germanic * walha-, "foreigner, Roman, Celt", whence the English word 'Welsh' (Old English wælisċ). Proto-Germanic *walha comes from the name of the Volcae, a Celtic tribe who lived first in southern Germany and central Europe, then migrated to Gaul. This means that English Gaul, despite its superficial similarity, is not actually derived from Latin Gallia (which should have produced * Jaille in French), though it does refer to the same ancient region.

Celtic refers to a language family and, more generally, means "of the Celts" or "in the style of the Celts". Several archaeological cultures are considered Celtic, based on unique sets of artefacts. The link between language and artefact is aided by the presence of inscriptions. The modern idea of a Celtic cultural identity or "Celticity" focuses on similarities among languages, works of art, and classical texts, and sometimes also among material artefacts, social organisation, homeland and mythology. Earlier theories held that these similarities suggest a common "racial" ("race" is contemporarily an invalid epistemolical and genetic concept) origin for the various Celtic peoples, but more recent theories hold that they reflect a common cultural and linguistic heritage more than a genetic one. Celtic cultures seem to have been diverse, with the use of a Celtic language being the main thing they had in common.

Today, the term 'Celtic' generally refers to the languages and cultures of Ireland, Scotland, Wales, Cornwall, the Isle of Man, and Brittany; also called the Celtic nations. These are the regions where Celtic languages are still spoken to some extent. The four are Irish, Scottish Gaelic, Welsh, and Breton; plus two recent revivals, Cornish (a Brittonic language) and Manx (a Goidelic language). There are also attempts to reconstruct Cumbric, a Brittonic language of northern Britain. Celtic regions of mainland Europe are those whose residents claim a Celtic heritage, but where no Celtic language survives; these include western Iberia, i.e. Portugal and north-central Spain (Galicia, Asturias, Cantabria, Castile and León, Extremadura).

Continental Celts are the Celtic-speaking people of mainland Europe and Insular Celts are the Celtic-speaking people of the British and Irish islands, and their descendants. The Celts of Brittany derive their language from migrating Insular Celts from Britain and so are grouped accordingly.