Gimwa mas essentially nothing other than brahman, only a technical difference. But it has a practical significance. It shows you the way of sadana. We cannot deny that we are in sam sara. If our real self is not the givatma, then the quest to be enlightened also seems to be moved.
Swami Sarvapriyananda teaches the Katha Upanishad, which is one of the most popular Upanishads. The scripture concerns the story of a young man who goes to the house of death to find out what happens after death. The reply describes the nature of reality and the meaning of life.