LamRim is the Tibetan term for "Stages of the Path". It is the fundamental instruction manual for Buddhist life and practice.
The Indian teacher, Atisha, brought this collection of the Buddha's teachings, which he called "A Lamp for the Path to Enlightenment", to Tibet in the 11th century.
Khensur Rinopche's teachings are based on Lama Tsongkapa's Lam-rim Chen-mo (The Great Treatise on the Stages of the Path of Enlightenment). The volume number in the title refers to this work.