Yiddish is the language of the central and eastern European Jews and their descendants. Written in the Hebrew alphabet, Yiddish became one of the world’s most widespread languages, appearing in most countries with a Jewish population by the 19th century. Along with Hebrew and Aramaic, it is one of the three major literary languages in Jewish history. For a brief introduction to the Yiddish language, you can visit http://www.bergen.org/AAST/Projects/Yiddish/English/yiddish.html. You can also check the website at http://www.ibiblio.org/yiddish/shul.html/ (Click on the Jewish Learning link), where you can learn all about Jewish culture, including the Yiddish language.
