Mitzvah is a Hebrew word that means "commandment." It's a word used by Jews to talk about things that God has commanded us to do. In Judaism, there are many commandments that we are supposed to keep - like loving our neighbor, honoring our parents, and keeping the Sabbath day holy. We call these things mitzvot, or good deeds. Doing mitzvot is another way to show love for God - and that's why we do them.