From the Avancemos textbooks:

To communicate with people from Spanish-speaking countries in a meaningful way, you need to know something about their culture (and their cultures are not all the same!). Vocabulary and grammar will help you learn what words to say and how to put them together, but culture will give you a better understanding of "how, when, and why to say what to whom." Culture is comprised of art, history, traditions, relationships, music, holidays, food, architecture, and pastimes. Below are just a few examples that we will learn about in Spanish class.