Tib., bKa-rgyud-pa: Oral Transmission
One of the four major traditions of Vajrayana and/or a member of this lineage. The Kagyu (short for Kagyudpa) tradition as a whole consists of many subdivisions, each bearing a different name depending on the respective founders or a specific monastery where a particular branch of Kagyu teaching originated.
In the very beginning, there were only two schools, Shangpa Kagyud and Dagpo Kagyud, the latter of which multiplied into at least 12 subdivisions - each with slight changes of emphasis on one or another teaching and practice.
However, apart from these twelve, Tibetan literature sometimes mentions additional schools bearing the name Kagyu; or as being closely related to this tradition. These are the Surmang Kagyu and the Orgyanpa (or Ugyen Nyendrup).
The Kagyudpa have, more than other Tibetan schools outside the old Nyingmapa, incorporated and transmitted many of the teachings from Bön and Indian Tantra; their teachings comprise Mahamudra and Dzogchen, the Naro Chödrug, rGyud bla-ma, Zab-mo snang-don, and brTag-pa gnyis-pa.
Ultimately, as one can judge from any list showing the Kagyud lineages, all these teachings are based on two streams of oral transmissions originating with Tilopa and Naropa.
Similar to Milarepa's Mila Gnubum, most of the important Kagyu-masters have composed teaching-songs, oral transmissions that have meanwhile been translted and published as the so-called Vajra Songs.