Tibetan, or Vajrayana, Buddhism is one of the four major schools of Mahayana Buddhism. The other three are Zen, Nichiren and Pure Land.
The term Mahayana has two distinct usages. Firstly, it refers to one of the two branches of Buddhism, the other being the Theravada. Mahayana Buddhism in this sense includes Tibetan Buddhism. Secondly, within Tibetan Buddhism, Mahayana refers to the second of the three levels of teachings, the other two being Hinayana and Vajrayana.
In some of the other schools of Mahayana Buddhism, the studying of sutras plays a crucial role in understanding reality. In Tibetan Buddhism, more emphasis is placed on studying the texts of the Prasangika-Madyamaka school (supposedly derived from Nagarjuna's teachings). Also some schools of Tibetan Buddhism constantly engage in philosophical debates on Buddhist principles to cultivate their wisdom. However, it must be noted that both the the Mahayana sutras and Prasangika-Madyamaka schools study the emptiness philosophy of Nagarjuna. So, in essence, they should be the same (differences only arising in the conceptual dimension).
The most famous book in Tibetan Buddhism is the Tibetan Book of the Dead, which can be seen not only literally as dealing with the states after death, but also with the consciousness states.
Another difference betwen Tibetan Buddhism and other Mahayana schools is that Tibetan Buddhists will often practice tantra, which they believe is higher than the highest practices of the other Mahayana schools.
If I understand your question correctly, Zen developed out of the Mahayana tradition. Tibetan tradition is different from both Mahayana and Zen.
mahayana is one of two major Buddhism exiting mahayana is one of two major Buddhism exiting
Tibetan Buddhism is collectively called vajrayana buddhism.
Thervada Buddhism focuses on the Buddha's wisdom, where as Mahayana Buddhism focuses on the Buddha's compassion.
Around 185 Million people are Mahayana Buddhists. Source: http://en.wikipedia.org/wiki/Buddhism#Mahayana
-Theravada Buddhism -Mahayana Buddhism (Zen)
Thervada Buddhism focuses on the Buddha's wisdom, where as Mahayana Buddhism focuses on the Buddha's compassion.
zen, mahayana and therevana are the different types of Buddhism The is Hinayana the original of the buddha, Mahayana, Vajrayana, and Nagarjuna
Mahayana Buddhism.
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Mahayana Buddhism
To discuss different branches of Buddhism is to discuss different sects or varieties of Buddhism. Buddhist scriptures are commonly divided into Theravada, Mahayana, and Vajrayana. Zen Buddhism is a kind of Mahayana Buddhism. .