During the latter Vedic period, Varnas came to be birth-based rather than profession-based (as were in Rig Vedic period).
Development of new professions gave rise to ‘jatis.’ But the jati system was not yet as rigid as it became during the period of the sutras.
The Rig Veda describes Vishvamitra as a rishi, but Aitareya Brahmana mentions him as Kshatriya.
The fourth Varna, i.e. Sudra were deprived of the rights of performing sacrifices, learning the sacred texts and of even holding landed property.
The concept of untouchability had not acquired its ugly form.
The individuals such as Kavasha, Vatsa, and Satyakama Jabala were born in non-Brahman jatis, but came to be known as the great Brahmans.
This was period of the development of a vast and varied Vedic literature.
The Upanishads were evolved as the highest level of intellectual attainments.
Education began with the ‘Upanayana’ ceremony.
The aim of learning was to get success in both worldly as well as spiritual life. Therefore It was necessary to learn faith, retention of knowledge acquired, posterity, wealth, longevity, and immortality.
The duties of pupils were well defined and there were stages of studies.
The pupils were taught at the homes of their teachers where they lived as family members and participated in the household works also.
For an advanced study, there were academies and circles of philosophical discussions.
Educated house holder may carry on their quest of knowledge by mutual discussions and regularly visiting the distinguished sages and learned scholars at different centers.
A great motivation of learning came from the assemblies of learned men; normally, organized and invited by the kings.
Parishads were established in different Janapadas with kings’ support.
Brihadaranyaka Upanishad described that king Janak of Videha organized a conference of the learned people. The major participants in this conference were Yajnavaikya, Uddalaka Aruni, Sakalya, Gargi, etc.
Yajnavalkya defeated all the participants in discussions and was declared as the most learned and wise.
Gargi and Maitreyi were the learned women. Their status shows that women were allowed to take an active part in the intellectual quest.
During this period, Kshatriyas begins to participate in the intellectual pursuit.
Some well-known Kshatriyas scholars were −
Janaka − the king of Videha,
Pravahana Jaivali − the king of Panchala, and
Asvapati Kaikeya − the king of Kasi.
These scholars (mentioned above) had acquired such distinction that even the learned Brahmans came to them for further instructions.
It is mentioned that Yajnavalkya, after completing his education with Uddalaka Aruni, went to Janaka (a king and Kshatriya) to study philosophy and other subjects.
The Chhandogya Upanishad described some subjects as the study of Vedas, namely Mathematics, Mineralogy, Logic, Ethics, Military Science, Astronomy, Science dealing with poisons, Fine Arts and Crafts, Music, and Medical Sciences.
The Mundaka Upanishad classifies all the subjects of study under Apara vidya.
In Mundaka Upanishad, the term Para vidya was used for the highest knowledge i.e. the knowledge of atman that involves knowledge of life, death, God, etc.
Atharvanaveda dealt with economic aspect. It described many prayers to bring economic prosperity for the success of farmers, shepherds, merchants, and so on.
Atharvanaveda explained prayers for ploughing, sowing, rains, and an increase in cattle, wealth, and exorcism against beasts, wild animals, and robbers.
The plough was known as Sira and the furrow Sita.
Cow dung was used as manure.
It is mentioned that six, eight, and sometimes even twenty-four oxen were used to pull a plough.
Many types of grains were grown, such as rice, barley, beans, and sesame. Their seasons are also mentioned as barley sown in winter, ripened in summer; rice sown in the rains, reaped in autumn and son on.
The Satapatha Brahmana mentions various operations of agriculture such as ploughing, sowing, reaping, and threshing
The Atharvanaveda discussed that drought and excess rains threatened agriculture.
The Atharvanaveda mentioned that hymens to worship the cow and the death penalty were prescribed for cow killing.
Moneylending was also in trend; normally, practiced by Rich merchants.
Specific weight and measuring units were also known.
Niska and Satamana were the units of currency.
Bargaining in the market was known from the Rig Vedic times itself.
Aitareya Brahmana speaks of the "inexhaustible sea" and "the sea as encircling the earth". It shows that sea-borne trade was well known.
The term Bali was used for a voluntary gift to chief (initially), but later on, it become a regular tax. It was collected to maintain the political and administrative structure.
During this period, a noticeable development in industry and occupations was seen.
Various occupations were mentioned such as: fishermen, fire and rangers, washer men, barbers, butchers, elephant-keepers, footmen, messengers, makers of jewels, baskets, ropes, dyes, chariots, bows, smelters, smiths, potters, etc. Besides, merchants, long distance caravans, and sea trade were also mentioned.
The Rig Veda describes only one metal as ‘ayas,’ which has been identified as copper. But during this period, a new metal i.e. iron, came into existence. Therefore, we get the term ‘syam ayas’ (iron) and ‘lohit ayas’ (copper). Apart from this gold, lead and tin are also mentioned.
Iron was used for making weapons and other objects like nail-parers, hammers, clamps, ploughshares etc. and Copper was used for making vessels.
Silver (rajat) and Gold were used for making ornaments, dishes, etc.
The Brahmanas recorded the growth of ritualism and ceremonial religion and the consequent growth of priesthood.
During the Rig Vedic period, large-scale ceremonies required maximum seven priests and two chief priests, but in the later Vedic period, the large-scale ceremonies required seventeen priests.
Several rites and ceremonies were come into practice as a means of attaining success in life in this world or the bliss in heaven.
The idea of penance and meditation took the precedence. Men took to ascetic practices under the belief that they would not only gain heaven, but also develop "mystic, extraordinary, and superhuman faculties".
During the later Vedic period, simple religious worship of the Rig Vedic period was replaced by elaborated rites and ceremonies and ascetic practices on one hand.
Whereas on the other, the intellectual pursuit of the people continued with the conviction that salvation was attainable only through the true knowledge.
The Upanishad contains philosophical treatises and there are about 200 Upanishads.
The Brihadaranyaka and Chhandogya were the oldest Upanishad. They contain bold speculations about the eternal problems of human thought concerning God, man, and the universe etc.
The Upanishads are considered as an important contribution of India towards the world's stock of spiritual thought.
Vedas, Brahmanas, and Upanishads give enough ideas about the sciences of this period.
The term ‘Ganita’, was used for the ‘Mathematics,’ which includes Arithmetic (Anka Ganita), Geometry (Rekha Ganita), Algebra (Bija Ganita), Astronomy and Astrology (Jyotisa).
The Vedic people knew the methods of making squares equal in area to triangles, circles, and calculate the sums and differences of the squares. Besides, Cubes, cube roots, square roots, and under roots were also known and used.
The Zero was known in Rig Vedic times and was frequently used in calculations and to record large numbers.
Astronomy was well developed. They were aware of the movement of heavenly bodies and able to calculate about their positions at different times. They had prepared accurate calendars and predicting the time of solar and lunar eclipses.
The Vedic people knew that the earth moves on its own axis and around the Sun. Further, moon moves around the earth. They also tried to calculate the time period taken for revolution and distances among heavenly bodies from the Sun. The results of these calculations are almost the same as the ones done by modern methods.