History of responsa in Judaism spans a period of 1,700 years. Responsa constitute a special class of rabbinic literature, differing in form, but not necessarily in content, from Rabbinic commentaries devoted to the exegesis of the Bible, the Mishnah, the Talmud, and halakha (the codes of Jewish religious law). The codes themselves contain the rules for ordinary incidents of life. The responsa literature covers all these topics and more. The mode, style and subject matter have changed as a function of the travels of the Jewish people and of the development of other halakhic literature, particularly the codes.