The Sanskrit word kriya means "action." Yoga can mean the practices used to facilitate overall well-being and spiritual growth, or oneness-consciousness: the final result of practice. In Patanjali's yoga-sutras, a two thousand year old treatise on superconscious meditation, kriya yoga is defined as discipline of mental and sensory impulses, self analysis, profound study of metaphysics (higher realities), meditation, and surrender of ordinary self-consciousness (egoism) in favor of God-realization.
Kriya yoga is a concentrated approach to Self-discovery and spiritual enlightenment: complete awakening to full knowledge of the Infinite and of cosmic processes. It includes the most effective processes of all systems of yoga, with emphasis on wholesome, constructive living and superconscious meditation practice. The purpose of kriya yoga practice is to restore the practitioner's awareness to wholeness. This is accomplished by acquiring knowledge of one's true nature as a spiritual being; cultivating rational thinking, emotional balance, and physical health; purposeful living; and meditation.
To facilitate the unfoldment of innate qualities and elicit superconscious states, specific meditation techniques are taught and practiced. Beginning meditators are usually taught how to use a simple word or sound (mantra) to focus attention. After a period of preparatory study and practice, initiation into advanced meditation processes can be requested.
Although kriya yoga has been known and practiced for centuries, it was Roy Eugene Davis' guru, Paramahansa Yogananda, who first emphasized it in the west. Yogananda traveled from India to America in 1920 and lectured, wrote, and trained disciples for 32 years before his passing in 1952. His best known book, Autobiography of a Yogi, is now published in multiple languages around the world.