Jnana Yoga or The Yoga of Knowledge is a book of lectures by Swami Vivekananda as transcribed by Joseph Josiah Goodwin. These lectures were delivered mostly in New York.
In this book, Vivekananda explains the knowledge of the Vedas, Upanishads, and the Bhagavad Gita in a scientific manner.
According to him, knowledge is the ultimate goal. It is only knowledge which can give us freedom from Maya or illusion.
The book also touches upon other important Hindu philosophies like the atman, cosmos, immortality etc.
Jnana-Yoga, along with Karma-Yoga, Bhakti-Yoga, and Raja-Yoga, is a classic book on Hindu philosophy.