The Nyingma (ancient) school of Tibetan or Vajrayana Buddhism was founded in the eighth century by the great enlightened Indian tantric master Padmasambhava, "the second Buddha," and is the oldest of the four schools of Tibetan Buddhism (Nyingma, Kagyu, Sakya, and Gelugpa). Its teachings, transmissions and lineage of enlightened masters have continued unbroken to this day.
The goal of spiritual practice within the Vajrayana tradition is to become a Buddha by following the bodhisattva path. Motivation is a vital component of Vajrayana practice, and all practices are undertaken with the motivation to achieve Buddhahood for the benefit of all sentient beings.
The Vajrayana is based on the concept of "skillful means" as formulated in Mahayana Buddhism. It is a system of lineages, whereby those who receive initiation and permission to practice are seen to share in the mindstream of the realisation of the Vajra Master. In the Vajrayana these skillful means mainly relate to tantric, Mahamudra or Dzogchen practices. According to Vajrayana, we are trapped in this realm of endless birth and death because of our impure perceptions. We believe that what we see is solid, ordinary, and defiled. The antidote to this is to develop pure perception.
According to the traditions and lineages, the Vajrayana techniques provide an accelerated path to enlightenment. Whereas earlier (Theravada and Mahayana) schools might provide ways to achieve nirvana over the course of many lifetimes, Vajrayana techniques are said to make full enlightenment or buddhahood possible in a shorter time, perhaps in a single lifetime.
Vajrayana Buddhists do not claim that other practices are invalid; on the contrary, the teachings from Theravada or Mahayana traditions are said to lay an essential foundational understanding on which the Vajrayana practices may be built. While the Mahayana and Theravada paths are said to be paths to enlightenment in their own right, the teachings from each of those vehicles must be heeded for the Vajrayana techniques to be effective.