Today, the Spanish language is the second, only to Chinese, as the most commonly spoken language in the world.
It was first introduced to South America by Christopher Columbus, in 1492, when we began his famous voyage from Spain to seek a new route to Asia. Unintentionally, he landed in the Americas and spread the language trough the New World.
As a result of this conquest, Spanish has matured in culturally disparate locations and therefore there are significant differences in accents, grammar and vocabulary in different parts of the Spanish speaking world.
Despite all these differences, you will still be able to communicate with a Spanish speaker from Spain or from Latin American. Imagine the English language spoken in the US, Australia and Great Britain, if we take into account the different accents and vocabulary, English might particular to every country, nevertheless those differences don´t hinder communication.
It is the same case for Castilian and Latin American Spanish, they are mutually intelligible, however, there are some differences worth mentioning:
-Different ways of addressing people: tú/vos/usted ( if you are speaking to only one person) and vosostros/ ustedes ( if you are speaking to two or more people); they are all equivalent to the English ¨you¨ and each of them varying in degrees of formality.
In Latin American Spanish, only ustedes is used when addressing more than one person; however, in Castillian Spanish, you have the choice to use either vosotros or ustedes.
Remember this as it is probably the most important difference between Castilian and Latin American Spanish.