CASTELLANO Castellano (Castilian) is the official term for Spanish used in the Spanish Constitution of 1978, but “español“ (Spanish) and “lengua española” (Spanish language) are often used when referring to Spanish as opposed to French, Italian or German, and also in linguistic or academic contexts. Elsewhere, the term “español” is often avoided because of its associations with either the former colonizing country (in the case of Latin America) or (in Spain) with the domination of Spanish over the other languages spoken in Spain (principally Catalan, Basque and Galician).
In the Spanish-speaking world castellano rather than español is a very common term for the Spanish language. Under the Spanish Constitution castellano is Spain's official language, but in some of the Comunidades Autónomas it shares official status with another language. Use of one or other term in Spain will depend on where the speaker is from, and where they place themselves in the linguistic debate.