Chandogya Upanishad is the part of Chandogya Brahaman and is associated with Sama Veda. It is ranked ninth in the Muktika canon of hundred and eight Upanishadas. The Chandogya Upanishad depicts the importance and greatness of universal holy syllable `Om Mantra` and the significance of vital life force or `Prana`. Chandogya Upanishad contains ten chapters. The third chapter has been divided into 19 Khandas that have been described below:

1st Khanda
The first khanda deals with the Honey Doctrine or the Madhu Vidya of the Rig Veda. The sun is the honey of the gods. The heaven is the arched bamboo, the atmosphere the hive: the vapours are the eggs. Of the sun the eastern beams are the eastern honey cells; the Rig hymns are the manufacturers of honey; the Rig Veda form the flowers, and the fluids are nectars

2nd Khanda
The second khanda deals with the Honey Doctrine of the Yajur Veda. The southern beams are verily the southern honey cells; the Yajar hymns are the honey makers; the Yajur Veda from the flowers; and the fluids are nectars,

3rd Chapter
The third khanda deals with the Honey Doctrine of the Sama Veda. The western rays of the sun are the western honey cells, the Saman verses are the bees, The Sama Veda is the flower and the water is the nectar.

4th Chapter
The fourth khanda deals with the Honey Doctrine of the Atharva Veda. The northern rays of the sun are the northern honey cells, the verses of the Atharvangirasa are the bees, the Itihasa purana is the flower and the water is the nectar.

5th Chapter
The fifth khanda also deals with the Honey Doctrine. The upward rays are the upper honey cells, the secret teachings of the Upanishads are the bees; Brahman is the flower, and its fluids are nectars.

6th Khanda
The sixth khanda deals with the meditation on the Vasus. The Vasus live on the first of these nectars with Agni (fire) at their head. The Devas neither eat nor drink, they only gratify themselves by its sight of the nectar.

7th Khanda
The seventh khanda deals with the meditation on the Rudras. On the second of these nectars the Rudras live, with Indra at their head. Truly, the gods do not eat or drink. They are satisfied by looking at the nectar. One who realises this becomes one of the Rudras.

8th Khanda
The eighth khanda deals with the meditation on the Aditya. He who thus knows this nectar becomes one of the Adityas along with Varuna at their head.

9th Khanda
The ninth khanda states upon meditation on the Maruts. The Maruta live on the fourth of these nectars with Soma at their head. One who realises this nectar becomes one of the Maruts with Soma at their head.

10th Khanda
The tenth khanda states about the meditation on the Sadhyas. They live on the fifth of these nectars with Brahma at their head. The gods do not eat or drink. They remain satisfied by merely looking at the nectar. He who knows this nectar becomes one of the Sadhyas with Brahma at their head.

11th Khanda
The eleventh khanda states about the result of the meditation on the honey. After rising upwards the sun sets no more. It remains alone in the centre. One who knows the Brahman, the sun does not rise or set. For him everything becomes eternal. This doctrine was told by Lord Brahma told to Prajapati, Prajapati to Manu and Manu to his offspring. Uddalaka Aruni`s father narrated him his doctrine.

12th Khanda
The twelfth Khanda deals with meditation on the Gayatri. All this creation is Gayatri. Speech is Gayatri and by speech all this creation is recited and preserved. The Gayatri is this earth and on this earth are all creatures sustained. Thus, gayatri is everything, whatever exists here. In man, that Gayatri is also the body as the Pranas exist within this body and do not go beyond.

13th Khanda
The thirteenth Khanda deals with meditation on the door keepers. There are five gates to heaven. The eastern gate is breath, Prana which is eye and that is Aditya, the sun. It must be adored as brightness and the source of food. The on the southern gate is the vyana, the ear that is the moon. One should meditate on that as prosperity and fame. That on the western gate is the apana that is speech that is Agni (fire). One should meditate on that as the radiance of Brahman and the source of food. That which is the northern gate is the samana that is the mind that is Parjanya, the rain god. One should adore it as fame and beauty. That which is the upper gate is the udana that is Vayu that is the akasa. One should adore it as strength and greatness.

14th Khanda
The fourteenth Khanda states about the Sandilya Doctrine. According to it whatever exists is Brahman. The universe evolves from it, it consists of the mind, whose body is subtle, whose form is light and whose nature is like the akasa. He resides within the heart of all. One who realises Him unites with Him. He is the Supreme Self from whom everything evolves.

15th Khanda
The fifteenth Khanda deals with the meditation on the Universe as a Chest. Its mid region is the inside and the earth its bottom. The quarters are its different corners and heaven is its lid, which is above. The eastern quarter is known as Juhu, the southern quarter Sahamana, the western quarter Rajni and the northern quarter Subhuta. Vayu the air is their child. He who is aware of this Vayu as the child of the quarters never weeps for his sons.

16th Khanda
The sixteenth Khanda talks about man as a sacrifice. The first twenty-four years of his life constitute the morning ritual, Pratah savana. The next forty-fourth year of his life constitutes the mid-day ritual. The next eighty fourth year of his life constitutes the afternoon ritual, the Jagati.

17th Khanda
The seventeenth Khanda continues to talk about man as a sacrifice. According to it when a man fells hungry, thirsty it is his initiatory rites. When he eats drinks and enjoys pleasures, he engages in Upasadas. When he laughs, eats and enjoys sexual intercourse it is Stuta and Sastra. Austerity, almsgiving, uprightness, non violence and truthfulness, these are the gifts for the priests.

18th Khanda
The eighteenth khanda depicts that the Mind and the Akasa are symbols of Brahman. According to it one should meditate on the mind, akasa as Brahman. That Brahman has four feet (quarters): speech is first foot, the Prana is the second foot, the eye is the third foot, the ear is fourth foot. With reference to gods Agni is one foot, Vayu is second foot, Aditya is the third foot and the quarters are the fourth foot. This is the twofold meditation with reference to the body and with reference to the gods.

19th Khanda
The nineteenth khanda deals with meditation on the Sun as Brahman. The sun is Brahman and is the teaching. From Him has evolved this universe. The creation of the universe has been explained here with the help of an egg. The universe when became existent it became an egg. It lay for a year and then from it appeared two halves; one half was of silver, the other of gold. The different parts of the egg then developed into different objects of the earth. One who understands these and meditates on the Brahman becomes united with Him and remains immortal.