What is the difference between dharana, dhyana, and samadhi in Patanjali's Yoga Sutras?

The three stages

Patanjali's Yoga Sutras describe eight limbs of yoga. The last three are all inward. Dharana comes first. The word means holding or binding. The mind is directed to one point, one object, one idea, and kept there. It still wanders and has to be brought back. That effort is the practice.

Dhyana comes next. It is often translated as meditation. Here the attention flows to the object without breaking. There is no longer a struggle to return. The mind rests on the object in a continuous, unbroken stream.

Samadhi is the third. The word is sometimes translated as absorption or integration. In samadhi the meditator no longer stands apart from the object. The sense of being a separate person watching the object fades. Only the object, in its own nature, remains. This is the deepest state of the three.

One movement, three names

Patanjali treats these three not as separate practices but as one movement deepening. The difference between them is the degree of mental unification. Dharana is effort. Dhyana is ease. Samadhi is merging. Together they are sometimes called samyama, a term for the three working as a whole. Practitioners in this tradition speak of samyama as a tool for understanding the nature of anything the mind rests on.

How people understand them today

In everyday yoga classes the word dhyana is used most often, simply to mean sitting quietly and meditating. Dharana and samadhi are less commonly taught at a beginner level. In deeper study, teachers tend to keep Patanjali's distinctions, pointing out that what most people call meditation is closer to dharana, the effort to concentrate, and that dhyana and samadhi are what that effort may eventually open into. How these stages are described and taught varies across lineages and teachers.