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ELI5: Difference between Sunni, Shia, Sufi, Ibadi, Ahmadiyya, and other types of Islam?

I have always wondered what exactly the differences between the differences between Islam are? Wasn't the Sunni/Shia split because of some sort of leadership split a long time ago? I heard Shia are typically more conservative (I don't know whether thats true or not). I also know that Ahmadiyya have really interesting views on Jesus' crucifixion (more what they believe happens after). 
Which groups are more liberal/conservative? Is there any denominations that I'm missing? Thanks.
gpt
*PS : I'll use Sunni as reference (X compared to Sunni) since it's the largest denomination in the Muslim community.*

I'll keep it as brief and as clear as possible :

- The Sunni chose Abu Bakr as the rightly Caliph (next leader) and the next ones were elected by the people, Sunni also follows the more conventional and conservative Islam (The Quran and Muhammad's life).

- The Shiites believed in Ali (Muhammad's cousin) and that he should be the next Caliph since he was from the same bloodline, they also believe in the concept of Imams that are the descendants of Ali and are somewhat to Islam what Popes are to Christianism, but more exempt of sins and more "divinely chosen". Shiites are also pretty hardcore when applying Sharia (Muslim law) compared to Sunnis, there are also other differences but they're pretty minor. 

- Sufism isn't a branch since a Sufi can be either Sunni or Shiite, it focuses more on the spiritualism and being closer to god with certain practices (think of it as the Buddhism of Islam if that makes sense). One thing to mention is that Islam's main focus is to balance between life and after life (be nice to everyone and pray to God), Sufism tends to focus on the afterlife more.

- Ibadi is a sect that isn't very open to outsiders but the general consensus is that it's a more relaxed compared to Sunnis when applying Sharia, still it follows the Sunni but as said before it's more relaxed.

*A note before explaining Ahmadi : Muslims believe of the coming of the awaited Mahdi (an ordinary man that will rule the Sunni) and the Second coming of Jesus to fight the false Messiah in the Judgement day, many people throughout history claimed to be the Mahdi.*
 
- Ahmadi believe that Muhammad isn't the last prophet and that the Mahdi is the next one, Mirza Ghulam Ahmed of Qadian (the founder) claims to be the Mahdi.

Those are pretty much the main differences between all the sects you'll ever hear about, some claim to apply Sharia correctly while others claim to have prophets.