From Latin castellānus, the concept of Spanish refers to the natural of Castile and to that pertaining or relative to this region of Spain . On the other hand, the word Castilian is used as a synonym for Spanish language , especially to make a distinction between the others tongues which are also spoken in the Spanish territory.

In this sense, Spanish is a Romance language of the Iberian group . It is one of the six official languages of the United Nations Organization (UN) and of the second most spoken language in the world according to the number of speakers who have it as mother tongue . On the other hand, Spanish is the second most studied language in the world, behind the English .
This language is a modern continuation of spoken Latin (known as Latin vulgar ), which began to develop after the disintegration of Roman empire . Thanks to its spread by America , Spanish is the Neo-Latin language that has reached the greatest diffusion.
Such is the growth that this language has experienced throughout history, which now concerns us that it has now become the second most spoken language in the world, after Mandarin Chinese, based on the number of people on the planet that They have as their mother tongue. Specifically, the figures that are considered determine that there are 420 million Spanish-speaking people.
Nor can we forget, among some curious facts, that it is one of the six official languages that the UN (United Nations Organization) has and that it is the third most used language on the Internet.
The majority of Spanish speakers are found in Latin America . Of the countries with a Spanish-speaking majority, just Spain and Equatorial Guinea they are outside America .
In U.S , the increase in the Latino population has generated a great advance in this language. Even in some regions like Miami , Spanish is spoken as much as English. According to Cervantes Institute , the number of Spanish students in the United States grew by 70% between 1986 and 1990 , given the importance that language began to acquire in the western world.
In addition to all of the above, we have to determine that there are other meanings for the Castilian term. Thus, it also refers to both the lord who owns a castle and the governor of that fortress.
In this area we have to underline, in the same way, that Castilian was also known to the gentleman who in the Middle Ages had weapons and two mounts that served him to work for a lord or a king during battles. Together with him and the rest of his vassals he fought in them and in the end what he obtained as a reward were lands that allowed him to increase his fortune and have a good position.
A time that we have referred to during which there was also a gold coin that was called Castilian and that was typical of the area of Castile.