Scholars contemplate that Vajrayana school developed as a result of royal courts sponsoring both Buddhism and Shaivism, i.e., they say, it was influenced by Hinduism.
The main deity is Tara (a lady)
It involved combining Brahmanical (Veda based) rituals with Buddhist philosophies.
Vajrayana is based on Mahayana Buddhist philosophy.
This school believes in Tantra’s, Mantras and Yantras superiority due to being a faster vehicle to liberation containing many skilful methods of tantric ritual.
According to this school, the mantra is an easy path to achieve Buddhahood without the difficulties as compared to striving for six perfections or Paramitas under Mahayana.
5.7 % of the world Buddhist population follows it.
Other countries following it include Tibet, Bhutan, Mongolia, Kalmykia, etc.