According to tantra, sentient being is buddha, buddha is sentient being; samsara is nirvana, nirvana is samsara. The basic nature of samsara and nirvana is the same, but because we are not yet enlightened and still have afflictions, we see buddha and sentient being, wisdom and afflictions, separately as pure and impure. The tantric path is called Vajrayana because of this view; it is unique in this sense.

~Depicted from GATEWAY TO VAJRAYANA PATH - Vajrayana Terminology