Spanish, also known as Castilian, is a language of the Romance branch of the Indo-European family. It is the official language of Spain and 19 other countries in Latin America. It is commonly used in several more countries, and is one of the six official languages of the United Nations. It is the most popular of the languages spoken in Spain, and the most widespread, thus garnering it the name Spanish.
Spanish has 5 vowel phonemes and 17 consonant phonemes:
Vowels: /a/ /e/ /i/ /o/ /u/
Consonants: /p/ /b/ /m/ /f/ /t/ /n/ /r/ /ɾ/ /ð/ /s/ /tʃ/ /l/ /ɲ/ /j/ /k/ /g/ /x/
Of course, in some dialects other phonemes crop up, such as /ʃ/ in Argentina and Uruguay (instead of /j/) and in Northern Mexico (replacing /tʃ/); /θ/ in Spain (in some instances replacing /s/); and /ʎ/ in some areas of Spain and South America (instead of /j/).