The Upanishads were said to be the reflection of teachings given by the teacher (or guru) to the student. The word Upanishad can be said to mean 'sitting near'. Key concepts talked about in the Upanishads include: the soul, reincarnation, karma, Brahman and liberation. The insights in the Upanishads were later put into systematic form by the Vedandanta (which means "end of the veda's"). In other words: the most famous of Indian philosophies - Advaita Vedanta - goes back to these teachings.