Castilian Spanish is the standard form of the Spanish language spoken in Spain. It is characterized by its distinct pronunciation, particularly the use of the "th" sound for the letters "c" and "z" in certain contexts. This variety of Spanish is often considered the basis for formal education and media in Spain. While Castilian Spanish is widely recognized, there are many regional dialects across the Spanish-speaking world. These dialects can differ in vocabulary, pronunciation, and grammar. Despite these variations, Castilian Spanish remains an important reference point for understanding the language as a whole.