To be exact, Yoga Alliance does not certify. It gives an accreditation. A school which has received the accreditation can be called a Registered Yoga School. A Yoga Alliance certification lays down a few guidelines that the registered school needs to follow. Amongst the guidelines, the first thing which acts as a prerequisite is the pre-defined syllabus. Additionally, trained and registered yoga teachers will teach the students. The main focus is on the depth of training. The accreditation mainly lays down the rules that one must follow. So, it essentially maintains unity.