Some accounts really criticized Islam as terrorism. In a broader sense, Islam is a religion of peace. Muslims believe that Islam is complete and the oneness to Allah (SWT) that was revealed many times before through prophets including Adam, Abraham, Moses and Jesus. As for the Quran, Muslims consider it to be the unaltered and final revelation of God and Muhammad (SAW) is the messenger.
In history of Islam during Al-Jahiliyyah period society does not allow the existence of women. Women are killed and cannot inherent any accounts from the society. Until it was changed and Islam is accepted by the believers.
Some people would say Islam brings terror. In parts of the world and in Islamic area of Middle East wars are severe. What had happened in Syria now? But this is not the basis for saying it brings terror. People must learn that in every religion their are customs, tradition and culture followed. The concept of Jihad is implemented in the law and from time to time situation gets worst, Muslims do Jihad.
Sunni and Shia, these two are division of Islam in which Muslims have differences in some aspect that they believed. Iran is dominant in Shia believers and Saudi Arabia particulary in Makkah is more on Sunni believers.
In Marawi City, Philippines last May 2017, a severe attack happened in the city. According to Imam Delabayan in my interview, the situation is a terrorism. He believed that fellow Muslims did not know what they are doing. They are not Muslims in doing. He is ashamed that only their fellow Muslims are affected. The city remained devastated and starting to build up about millions of losses. People think wise and makes mistake. People needs to know that Islam have its own concept and ideas about their religion and should not accused as terrorism. Yes, it is Islam that strictly motivate the Muslims and only Muslims did a zigzag actions but directly in the Qur'an as revealed a true Muslims brings peace and not of terrorism. Islam spread the message of peace, justice and equality. Peace is not simply an absence of war according to Islam. Every teaching of Islam is based on the principles of peace and avoidance.