Yoga can be many different things, depending on the person practicing, the practice itself, or even the day it is practiced. For example, on one day, yoga might be the means of relaxation at the end of the day, allowing for better sleep at night; the next day, it might be an invigorating practice for strength-building. One person may choose to practice only pranayama, or breathwork, to ease breathing conditions like asthma. In these ways, yoga is dynamic.

Yoga is all these things, and so much more, but when it gets down to the core essence of what yoga really is, it’s simple—yoga is the cessation of the fluctuations of the mind. The Yoga Sutra, Patanjali’s 2,000-year-old guidebook to yoga, lays out this true meaning of yoga in the very second sutra: Yogas citta vrtti nirodhah.

Ok, sure. But what does that mean exactly?

Usually, yoga class is initiated with a breathing or centering meditation or chant. These practices serve to center the mind. In today’s world, with the hustle and bustle of everyday life, the mind is anywhere but right here, right now. We try to do 10 things at once, while simultaneously planning tomorrow and lamenting what didn’t happen yesterday. In yoga, we bring ourselves back to the moment—over and over again.

Bringing yourself back to the moment is, essentially, cessation of the fluctuations of the mind—fluctuations of the mind being those thoughts about what you didn’t accomplish yesterday, what you need to do tomorrow, or even that long inner dialogue about what was underlying a comment from your coworker earlier today. These thoughts tend to clutter the mind because they don’t have much relevance to this moment. When we take time to bring our focus back to the moment—with breathwork, asana, drishti, concentration—we create space, so to speak, for insight.

So yes, yoga can be many things to many people—and it is—but the true essence of yoga pervades each and every yoga practice, even if only in small glimpses. That moment when you are able to bring your attention back to the breath—even for the twentieth time—is what yoga is all about.