Ashkenazi Jews are split into orthodox, chareidi, chassidish, modern orthodox, and then reform and conservative. Sefardim are just Sefardim. Nobody ever heard of a reform Sefardi. I want to understand how this happened.

1. Where did the denominations actually come from? My understanding is reform started in Germany in the 1800s after the haskala, and orthodoxy was the reaction, the Chatam Sofer and chadash assur min haTorah. Is that the real history, and were these labels ever a halachic category or just a social one?

2. Chassidus started with the Baal Shem Tov and the misnagdim fought it hard, the Gra and the cherem. Today chassidim and misnagdim are all just chareidim together. How did a fight that big turn into one camp, and what does that say about how real these divisions are?

3. Why did Sefardim never split? There was haskala in some Sefardi places too, but no reform movement came out of it. Is that because the haskala was really an Ashkenazi event, or because Sefardi psak worked differently, more flexible inside the tradition so nobody needed to break off?

4. Halachically, what is a denomination? If a person keeps the Shulchan Aruch, what does a label add or remove? Is there any real halachic difference in how the groups pasken, or is it all minhag and culture on top of the same halacha?

5. Practically, how should a person think about these labels? Are they a real part of Torah, or a 200 year old European argument that has nothing to do with being a Jew who keeps halacha?