Islamic Sects

There are 73 divisions in total in Islam, but the main branches, divisions, or sects of the Islamic belief system are Sunni and Shi'a
Eighty-five percent of Muslims are Sunni
The two main branches split after the death of Muhammad
There was a disagreement over who should lead the Muslims.
Shi'as and Sunnis split after prophet Muhammad died in 632.

Shi'as

The Shi'a believe that Imam Ali, Muhammad's cousin and son-in law should lead the Islamic state, while the Sunnis believed that the leader should be chosen through an election.
Shias believe that Allah (SWT) chose Imam Ali to be Muhammad's Khalifa (head of state) of Islam. Imam Ali was the cousin and son in law of Prophet Muhammad.
Shias love Ali more than Muhammad (PBUH) while Sunnis love prophet Muhammad the most, and Abu Bakr, Umar, Ali, and Uthman are equally respected as well.
Shias believe that they are to be considered descendants of Muhammad.

Sunnis believed Muhammad should rule and Shia believe Ali should rule
Sunnis chose Abu Bakr, the prophet's advisor to lead the Muslim state, Shias wanted Ali.

The divide between the Sunni and Shia happened because the Islamic prophet Muhammad had died
When Muhammad died it lead to a dispute over who should rule the Muslim state
Both the Sunni and Shia believe in the the prophet Muhammad.
Both of these two sects also have 3-4 subsets within them.
The two sects also believe that Islam is the true faith.
The Shi'a and Sunni also believe in one body.
They only follow the Qur'an.
The two sects also believe in the Five Pillars of Islam.
The two sects also believe that images or statues of the prophet Muhammad or God is sinful.

Shias changed the Quran and Sunnis still read it identically to the originally Quran
Sunnis pray 5 times a day, while Shias have three official prayers.
There are more Sunnis than Shias in the world.