What is a vinyasa, anyway?
The sanskrit word has several meanings. The most common usage is to define a specific linking sequence (based on the sun salutation — chaturanga/up dog/down dog) that is coordinated with the breath and gets you from pose to pose. The practice becomes a flow timed to the breath instead of just a series of discrete postures. The vinyasa gives rhythm to the practice, keeps the heat building, builds upper body strength and acts as a counterpose to stretch the legs and re-set the spine to neutral for the next sequence.