By Rabbi Yerachmiel D. Fried

Dear Rabbi Fried,
Thanks for your answer about the various names of God. That makes it easier to focus, knowing they’re all referring to various character traits of the same God. I would appreciate if you could elaborate on what those traits are we are referring to when we mention those names.
— Harvey L.
Dear Harvey,
We can try to touch on the very basic meaning of some of the more commonly mentioned names.

• Adonai, this is the most commonly used Name of God. This name means “master of all,” or as some will translate it, “master of the universe.”

• Yahweh, meaning “He was, He is and He will always be, the master of the universe Who brought everything into existence and keeps it going.”

This is a name we don’t ever actually pronounce; we say “Adonai” when it is written with the letters yud-hey-vov-hey. Only during the Temple worship was this name actually pronounced, by the Cohanim/priests. This is due to the name’s profound holiness.
In our times, it is never pronounced, and the Talmud says this will be the case until Messianic times. There are different opinions among the Kabbalistic masters whether one should have in mind the name one is pronouncing or the one we are referring to. Sephardic custom is to have in mind both, reflected in their Siddur, where the two names are actually writing with both intermingled together. I would suggest doing what you feel most comfortable.
This is the name most associated with God performing acts of loving kindness and compassion in the world.

• Elohim, meaning “master of all the powers of the universe.” This name teaches us that our belief is very different than that of many religions that believe various powers, such as the power of evil, run contrary or are at war with their god(s). Our belief is that God created all powers that exist for reasons of tikkun and free choice, and that He controls all such powers.

He will also destroy the powers of evil from the world, at the time He sees fit when they have run their course and finished their purpose. Since we, for the purpose of effecting a tikkun, have been empowered by God to control the universe with our actions, we were created in the “image of Elohim.”
This is the name used most in conjunction with God utilizing the trait of strict judgment and, when necessary, carrying out retribution in the world.

• El, a very common name that refers to God’s sustaining the world with His kindness, providing food for us and the animal kingdom. It also is the name that, according to the Kabbalists, starts off the 13 attributes of kindness that were revealed at the time the Jews repented over the sin of the golden calf. Those 13 traits form the foundation of our Yom Kippur services.

There is more to explain and there are more names as well, but I hope this helps you for the majority of the service.
Rabbi Yerachmiel D. Fried, noted scholar and author of numerous works on Jewish law, philosophy and Talmud, is founder and dean of DATA, the Dallas Kollel. Questions can be sent to him at yfried@sbcglobal.net.