Linked post from Torah.org
A mitzvah is a commandment -- one of the taryag mitzvot, 613 commandments, relating to Jewish observance and religious practice. The commandments are the centerpiece of Judaism because they are where faithfulness to God and His Torah translate into action! Every sphere of human activity falls under the Torah's authority. From rising in the morning to retiring at night, from birth until death, the commandments encompass every area of Jewish life.
from "SET IN STONE." Published by Targum Press