The Spanish that is normally referred in Latin America and across various countries of the world is a Latin American Spanish. Whereas, Castilian Spanish (Castillano or espanol) is referred to the pure Spanish or the oldest, real form of Spanish, spoken in the Northern and Central Spain. The term Castilian is used to differentiate the Spanish spoken in Spain from the Spanish spoken in Latin America.
The Castilian Spanish is derived from vulgar Latin of the Iberian Peninsula (Portugal and Spain). It is predecessor to the modern Spanish and is widely spread in the Northern and central parts of Spain. It is the official language in these regions and also the standard language used for education, TV and Radio programs.
The Spanish spoken in Southern Spain and in the surrounding parts of the Spain are different varieties of Spanish. The other varieties of Spanish are Galician (similar to Portuguese), Catalan (Similarities to Spanish and French) and Euskara or Basque (Similarities to French). Of these languages Galician and Catalan are Latin based languages and Euskara is a non-Latin Language. Another variety of Spanish called Andalusian Spanish is spoken in Southern Spain.
The Castilian Spanish varies from the Latin Spanish in terms of Pronunciation, vocabulary and grammar.