What is "qira'at"

In Islam, Qira'at, which means literally the readings, terminologically means the method of recitation. Traditionally, there are 10 recognised schools of qira'at, and each one derives its name from a famous reader of Quran recitation. Each Qira'at is then transmitted via a riwaya (transmission) named after its primary narrator. Each of the riwayas is the whole of the Qur'an as recited by a master in all the variants which are transmitted from him. It is a corupus of reciation. The forms of each recitation are referred to by the notable students of the master who recited them. So we will find the turuq (transmission lines) of so-and-so, the student of the master. Then under the Turuq, there are also the wujuh. We find the wajh of so-and-so from the tariq of so-and-so. There are about twenty riwayat and eighty turuq.