Halakhah comes from three sources: from the Torah, from laws instituted by the rabbis and from long-standing customs. Halakhah from any of these sources can be referred to as a mitzvah (commandment; plural: mitzvot). The word mitzvah is also commonly used in a casual way to refer to any good deed. Because of this imprecise usage, sophisticated halakhic discussions are careful to identify mitzvot as being mitzvot d'oraita (an Aramaic word meaning from the Torah) or mitzvot d'rabbanan (Aramaic for from the rabbis). A mitzvah that arises from custom is referred to as a minhag. Mitzvot from all three of these sources are binding, though there are differences in the way they are applied.