If you ever went to school here you will learn castellano (know commonly as Spanish-Español nowadays)
Today, the term "Castilian" is used in other ways too. Sometimes it is used to distinguish the north-central standard of Spanish from regional variations such as Andalusian (used in southern Spain). Sometimes it is used, not altogether accurately, to distinguish the Spanish of Spain from that of Latin America. And sometimes it is used simply as a synonym for Spanish, especially when referring to the "pure" Spanish promulgated by the Royal Spanish Academy (which itself preferred the term castellano in its dictionaries until the 1920s).
In Spain, a person's choice of terms to refer to the language — castellano or español, sometimes can have political implications. In many parts of Latin America, the Spanish language is known routinely as castellano rather than español.
The term (se habla Español) is commonly used to refer the spoken language of a particular country to a foreigner it's at lot less daunting for them to understand that than referring the language as Castellano they will not have a clue were this alien language come from.
Sorry for continuing with this of topic but I need to clear this misunderstanding why here the spoken and written language is called Castellano and not Español, it's the same but at the same time it's not the same.