(español), also called Castilian (castellano listen (help·info)), is a Romance language that originated in Castile, a region in Spain. Approximately 406 million people speak Spanish as a native language, making it the second-most-spoken language by number of native speakers after Mandarin.It also has 60 million speakers as a second language, and 20 million students as a foreign language. Spanish is one of the six official languages of the United Nations, and is used as an official language by the European Union and Mercosur.