Because there was so many studies about Islam that talking with detail, so in this case I'm only talking Islam with simple and from My opinion as a moeslem.
What is Islam ?Islam is a religion that given by God or in Islam called Allah to Muhammad the Prophet. Core this religion is believing in only one God (Allah) and this teached by
Abraham the Prophet. So Abraham The Prophet in Islam called The Father of Prophets because His tuition become source of tuition for Jewish, Christian and also Islam. Like Jewish and Christian that have a holly book, Islam also have it and it's called Al-Qur'an.
Who is Muhammad ?Before I'm talking about Muhammad, I must explain about the diference between Prophet and Rasul.
The Prophet is person who given tuitions by God but He don't have responsibility to teach that tuition to other people.
Rasul is kind o person who given tuition by God and He teach that tuition to other people who become His followers.
Like I'm talking before, Muhammad is a Prophet and Rasul who brought and teached Islam to the Universe. We as a moeslem believe that Muhammad is the last prophet and Rasul because it's explained on Al-Qur'an. On The Al-Qur'an, explained that there are 100.000 Prophet Prophet but Islam is only believe 525 Prophet and for Rasul Islam is only believe 25 Rasul include
Abraham,
Moses,
Isa (Yesus) and
Muhammad.
What is Al-Qur'an ?Al-Qur'an is a holly book for Islam. In the Muhammad The Rasul, Al-Qur'an given by God step by step because Muhammad couldn't read and write since He became a Rasul in age 40 Years old until He passed away on age 63 years old and Muhammad ask to His followers who can read and write to write this message from God on camel's skin or Qorma tree skin. and then, Khalifah Omar ibn Khattab who become a leader after Khalifah Abu Bakkar ask to re-write this hand writing become one book and the first Al-Qur'an finnished on Khalifah Utsman ibn Affan era.