Many books were revealed (sent) to the Prophets by Allah.
Four of them are important. They are 1. Tawrat; 2. Zabur; 3. Injil; and 4. Qur'an al-Majid.
You should know that:
1. Tawrat was revealed to Prophet Musa (A.S.)
2. Zabur was revealed to Prophet Dawood (A.S.)
3. Injil was revealed to Prophet ‘Isa (A.S.)
4. The Qur’an was revealed to our Holy Prophet Muhammad al-Mustafa (S.A.W.).
All previous books were cancelled by Allah when the Qur'an was sent. Now the Qur’an is the only authentic and true book which is to be followed by all men.