Originally understood as Temple service, but expanded to mean any service to God.
Related to: gemilut hasadimPerforming acts of kindness (hesed).
Often drawn from Pirkei Avot 1:2, "the world stands upon three things: the Torah, the Temple service (avodah), and the practice of acts of piety (gemilut hasadim).". See Pirkei Avot 1:2