The Qur'an consists of 114 chapters. A chapter is called a Surah. Each chapter has been given a different name. The first wordings of certain chapters have been used to name the chapter itself. Other surahs derive their name from a particular reference somewhere in its middle portion. There are yet other surahs which are named after the main theme therein. Some other surahs have names which highlight the basic issues discussed in them.
There is also much difference in the size of each surah. Indeed, there are surahs which vary in length from three small verses to lengthy surahs which have nearly three hundred.
Each verse of the surahs is called an aayath. In the length of the aayaths, too, there exists much disparity. The aayaths range from very short ones, which comprise a combination of a few sounds, to very lengthy ones indeed. Many aayaths are in themselves complete words. Then there are other aayaths which form full sentences only if put together. Similarly, there are aayaths which are a combination of complete words. The structure and length of the aayaths have all been decided by God Almighty Himself.