Shamatha is the Sanskrit name, and the form used across the Tibetan and East Asian Mahayana traditions, for the meditation of calm abiding, the cultivation of a stable, settled attention resting one-pointedly on its object. It is the counterpart, under a different transliteration, of the practice the southern Buddhist tradition calls samatha, and it names the same fundamental training: the gathering of a scattered mind into steadiness. In the Tibetan presentations it is very often taught as the foundation of the whole meditative path, the ground that must be laid before the more advanced practices of insight and of tantra can bear fruit.
The object of shamatha may be the breath, a small object or image placed before the meditator, a visualised form of a buddha, or simply the bare presence of awareness itself. As the mind is repeatedly returned to its object, agitation and dullness, the two great obstacles, are gradually overcome, and the attention becomes clear, stable and pliant.