“You may never have heard of him but Tirumalai Krishnamacharya influenced or perhaps even invented your yoga. Whether you practice the dynamic series of Pattabhi Jois, Astanga the refined alignments of B. K. S. Iyengar, the classical postures of Indra Devi, or the customized Vinyasa or viniyoga, your practice stems from one source: a five-foot, two-inch Brahmin born more than one hundred years ago in a small South India village“ - Tirumalai Krishnamacharya on Wikipedia
Vinyasa means movement between poses. Ha – tha means sun and moon, Flow – moving in balanced union. Both Hatha Flow and Vinyasa Flow will sycnchronize the breath with movement. Vinyasa is often more choreographed in an uninterrupted flow. When I am teaching any Flow class, my objective is, to find the calm amongst the storm, the stillness in the movement, the flow in the stillness. A Hatha Flow class is really as it says on the tin, classical hatha postures that flow from one to another with some pauses for added instruction and teacher demonstration
If the class is Dynamic you will have the opportunity to deepen the strength of your practise by holding the poses for longer and maybe, if appropriate, for your level, you can try other postures that require more strength and flexibility, balance and control.
A safe practise. A mindful practise which requires constant moment to moment attention – this is yoga. A truthful practise ‘satya’, an ahimsa practise – non harmful, fully embodied and joyful – that is yoga. As a teacher of Hatha, Hatha Flow, Astanga and Vinyasa Flow I apply all of these principles in all of my classes as well as my personal practise. This attitude has served me well for over 20 years now.
Finallly here to say that every teacher will have their own individual take on these styles, bringing forth and blending in their unique teachings and approach.