Orach Chayim

Orach Chayim is a section of Rabbi Jacob ben Asher's compilation of halakha (Jewish law), Arba'ah Turim. This section treats all aspects of Jewish law primarily pertinent to the Jewish calendar (whether the daily, weekly, monthly, or annual calendar). These aspects include, but are not limited to: prayer, the Sabbath, Festivals, tefillin (phylacteries) and tzitzit (ritual fringes), and public Torah reading.

Later on, Rabbi Yosef Karo modeled the framework of his own compilation of practical Jewish Law after the Arba'ah Turim. Many later commentators used this framework, as well. Thus, Orach Chayim in common usage refers to an area of halakha, non-specific to Rabbi Jacob ben Asher's compilation.