Shaiva Tantra is a branch of Hinduism that focuses on the worship of Lord Shiva, the destroyer and transformer deity. It is believed to be one of the oldest and most influential forms of Tantra, which is a spiritual tradition that seeks to awaken the practitioner's inner energy and connect them with the divine.

There are several schools or lineages within Shaiva Tantra, each with its own unique approach and practices. These include the Kashmir Shaivism, Kaula Tantra, Trika Shaivism, and Pashupata Shaivism.

Kashmir Shaivism is considered to be the most prominent and well-known school of Shaiva Tantra. It originated in the Kashmir region of India and is also known as the Trika school. This school emphasizes the concept of non-dualism, where the individual self (Atman) and the universal consciousness (Shiva) are seen as one and the same. It also focuses on the practices of mantra, meditation, and ritual worship to connect with the divine.

Kaula Tantra, also known as the Kula school, is another important lineage of Shaiva Tantra. It is a more esoteric and secretive tradition that focuses on the awakening of the inner energy (Kundalini) through the use of intense rituals, including sexual practices. This school also places a strong emphasis on the worship of the divine feminine, often represented as the consort of Lord Shiva, Goddess Shakti.

Trika Shaivism, also known as the Shaiva Siddhanta school, is a more philosophical approach to Shaiva Tantra. It emphasizes the concept of Shiva as the ultimate reality and the source of all creation. This school also incorporates elements of yoga, meditation, and ritual worship to attain spiritual liberation.

Pashupata Shaivism is one of the oldest lineages of Shaiva Tantra, dating back to the 5th century BCE. It is based on the teachings of the sage Lakulisha and focuses on the worship of Lord Shiva as the supreme deity. This school also emphasizes the importance of ethical conduct and social responsibility in the path to spiritual enlightenment.

In addition to these major schools, there are also other lineages within Shaiva Tantra, such as the Nath tradition, which combines elements of Shaivism and Tantra with the teachings of the yogic sage Gorakshanath.

Overall, the different schools of Shaiva Tantra may have their own unique practices and beliefs, but they all share the common goal of connecting with the divine and attaining spiritual liberation through the worship of Lord Shiva.