Nichiren Buddhism is a branch of Mahayana Buddhism that was founded by the Japanese monk Nichiren in the 13th century. It is based on the belief that the Lotus Sutra is the ultimate and most complete teaching of the Buddha, and that faith in this sutra is the path to enlightenment and liberation.

The Lotus Sutra is a collection of teachings and parables that were originally taught by the historical Buddha, Shakyamuni, towards the end of his life. It emphasizes the concept of "Buddha nature," the inherent potential for enlightenment that exists within all beings. Nichiren Buddhists believe that by chanting the mantra "Nam-myoho-renge-kyo," which means "devotion to the Lotus Sutra," one can tap into this Buddha nature and achieve enlightenment in this lifetime.

One of the key teachings of Nichiren Buddhism is the concept of the "three treasures" – the Buddha, the Dharma (teachings), and the Sangha (community). Nichiren believed that the true teachings of the Buddha had been lost or distorted over time, and that the Lotus Sutra was the only true and complete teaching. He also emphasized the importance of the Sangha, or community, in supporting each other on the path to enlightenment.

Nichiren Buddhism also places a strong emphasis on social and political engagement. Nichiren believed that the world was in a state of decline, and that it was the responsibility of Buddhists to actively work towards creating a more peaceful and just society. This is reflected in the practice of "shakubuku," or "breaking and subduing," which involves actively challenging and converting those who hold different beliefs.

In terms of practice, Nichiren Buddhists primarily engage in chanting and reciting the Lotus Sutra, as well as studying its teachings. They also often participate in group chanting sessions, known as "gongyo," and may also engage in meditation and other forms of spiritual practice.

In summary, Nichiren Buddhism is a branch of Mahayana Buddhism that places faith in the Lotus Sutra as the ultimate path to enlightenment. Its teachings emphasize the importance of community and social engagement, and its practices center around chanting and studying the Lotus Sutra.