Vinyasa is a style of yoga characterised by stringing postures together so that you move from one to another, seamlessly, using breath. Commonly referred to as 'flow' yoga, it is sometimes confused with ‘power yoga’.
Vinyasa classes offer a variety of postures and no two classes are ever alike. The opposite would be 'fixed forms' such as Bikram yoga, which features the same 26 postures in every class, or Ashtanga, which has the same sequence every time. The variable nature of Vinyasa yoga helps to develop a more balanced body as well as prevent repetitive motion injuries that can happen if you are always doing the same thing every day. As a philosophy, Vinyasa recognises the temporary nature of things. We enter into a posture, are there for a while and then leave.
While Vinyasa, or Vinyasa-Krama, dates back to the Vedic age - the earliest period of yoga thousands of years ago - it referred to a series, or sequence, of steps to make something sacred. The movement practice of Vinyasa is said to begin with T Krishnamacharya who has had the largest influence on how yoga, in general, is practised today.
Put all this together, and Vinyasa is a breath-initiated practice that connects every action of our life with the intention of moving towards what is sacred or most important to us.
While Vinyasa yoga is one of the most popular forms of the practice in the world today, it is not well understood.

As with many things in yoga, the definition is dependent on the context and on whom you ask. Below are the more common definitions.
'The Sanskrit word Vinyasa comes from a prefix vi, which means variation, and a suffix nyasa, which means ‘within prescribed parameters”'. Srivatsa Ramaswami, student of Krishnamacharya for more than thirty years.
He goes on to refer to classical yoga, from the Yoga Sutras of Patanjali, for the specific parameters:
The term Vinyasa is derived from nyasa, meaning 'to place', and vi, meaning 'in a special way'. This indicates that we are not 'throwing our bodies around' but are bringing consciousness to each movement in each moment.
Shiva Rea adds, 'Vinyasa in its original meaning from the early Tantras is understood as the "sequence of consciousness", or how life unfolds from … the creative pulse of life'.
Vinyasa can be defined as our external movements that are an expression of how we think and feel.
Synonyms: Continuous. Seamless. Integrated. Change. Rhythm. Evolve. Cycle. Connected. Movement.

'[Vinyasa] Flow yoga can be practiced in a vigorous, dynamic and stimulating manner and also as a soft, gentle, restorative practice'. Ganga White
A hallmark of Vinyasa Flow classes is the variation in sequence from class to class. (A sequence is any time two or more postures are strung together.) No two classes are alike.
In a fixed form system, such as Bikram, or Ashtanga yoga, the sequence remains the same to reveal what changes day-to-day - mainly us.
A variable form system, like Vinyasa, exists to help us see what is changeless and permanent throughout all of the change. This might be an intention or purpose, a way of thinking or connection to something greater than ourselves.
One other key aspect of the variation is it keeps your interest. Many practitioners move from the fixed forms to Vinyasa because they become bored.
'A powerful Vinyasa practice can shake things up to the point of calming things down'. Rusty Wells
prayatna saithilya ananta samapattibhyam II:47 Yoga Sutras of Patanjali
'Perfection in an Asana is achieved when the effort to perform it becomes effortless and the infinite being within is reached'. B.K.S. Iyengar
Krishnamacharya is attributed with being the architect of Vinyasa. He expands on the importance of it in his book 'Yoga Makaranda - The Nectar of Yoga'. A guest of his benefactor, a maharaja, or prince, Krishnamacharya taught adolescent boys at Mysore Palace. What better way to calm down active teenagers than with a lot of movement.
Who knew that insight is also perfect for calming the high-spirited mind of the modern world? Rishi Vamana is also credited with creating Vinyasa Yoga. The idea was to simultaneously embody the different facets of yoga: mudra, pranayama, meditation, asana and japa.
The first reference to Vinyasa dates back to the earliest yoga age called the Vedic Period. Here, Vinyasa was defined as a step-by-step process to make something sacred.
The Yoga Sutras of Patanjali also cite [vinyasa] krama:
ksana-pratiyogi parinamaparanta-nirgrahyah kramah IV:33
'The progression [of any object through Time] corresponds to a [series of] moments. It is perceivable at the final [moment] of change.
Nothing is static but changes every moment'. Edwin Bryant