Meditation, as most people picture it, is one activity with one measure: you sit, and by the end you are more or less calm. A good session is a settled one, a bad one is the mind refusing to stop, and the quiet you sometimes reach feels like the point of the whole thing.
Buddhism counts two things where that picture counts one. Calm is a skill, and it is real, but it is the skill that exists for the other's sake: a snow globe under a magnifying glass, where however good the lens, it finds nothing until the snow has settled. A session that went quiet and looked at nothing has done half the work. The two halves are usually grown together, and each has its own name.
Snow globe: hold it still, and the snow sinks until the glass is clear.
Samatha is calm abiding, the cultivation of stillness: gathering the scattered mind onto a single object until it settles and grows quiet. It is the Buddhist name for what yoga calls chitta vritti nirodhah, the stilling of the mind's fluctuations.
Magnifying glass: a steady lens shows what the eye passed over.
Vipassana is insight, clear seeing: once the water is still, looking into it, into the three marks of impermanence, unsatisfactoriness, and no-self.
Stillness makes seeing possible; seeing is what stillness is for. In this framework the two are trained as concentration (Dharana) and as inquiry in meditation (Dhyana).
How calm is built: the five marks of śamatha
Calm abiding is not a single switch but a sequence, and the tradition is unusually specific about its stages. Śamatha has five characteristics, and they arrive in order, each growing out of the one before.
- Stable attention — samādhi, attention that rests on its object without strain.
- Mindfulness — sati, the clear, bare knowing of what is present, moment to moment.
- Joy — pīti, a gladness that arises on its own once attention settles.
- Tranquility — passadhi, that joy maturing into a quiet, settled ease.
- Equanimity — upekkhā, the even, unshaken balance that tranquility ripens into.
The order is the teaching: you work with stable attention and mindfulness until joy emerges; joy matures into tranquility; and equanimity arises out of that. The two halves grow together for the same reason: attention and mindfulness build calm, calm makes insight possible; and the two together are what the tradition means by awakening.
Sati, mindfulness, is the same bare, non-judging knowing that the whole Mind priority trains: not thinking about experience, but knowing it as it happens. And one of the marks is an old friend. Upekkhā is the equanimity met among the Brahmaviharas, here turned inward, the same quality ripening in stillness rather than reaching toward others. The joy is a different one: pīti is the gladness of a mind that has settled, where the Brahmaviharas' joy, muditā, is gladness at another's good fortune.