Consumers want products whenever they have money, time and willingness to buy. Goods are produced in anticipation of such demands. They are stored in warehouses in different regional centres so that they can be distributed at the right time to the consumers.

i. Production takes place in one centre and consumers are spread throughout the country and world.
ii. Rail, air, sea and land transports bring the products to the place of consumer.

i) Boats like 'Padagu, Thimil, Thoni, Ambu, Odampunai' were used for domestic trade.
ii) Boats like 'kalam, Marakalam, Vangam,Navai' were used for foreign trade.

The place where the goods were sold was called "Angadi".

Day market was called as Nalangadi.

The important Ancient Trade centres in the coastal regions of Tamil Nadu are:
(i) Alambarai
(ii) Alagankulam
(iii) Pumpuhar
(iv) Marakkanam
(v) Vasavasamudram
(vi) Mylapore.

Trade and commerce was so common to Pandya Dynasty. Information collected from the diaries of foreign travellers, voyagers, mariners and adventurers of the ancient world highlighted the prosperity of trade in the Pandya country. The Hebrew and Latin literature, Archaeological remains in Aden, Alexandria, Java, Sumatra, and even China add support to the fact of existence of trade network in the Pandya country. Trade in copper, cloth, salt, flower, sandalwood, fish, paddy, cereals, pearls, etc., flourished during their period.

1. Each party to barter must have surplus stocks for the trade to take place.
2. Both buyers and sellers should require the goods of each other deseperately i.e., double coincidence of wants.
3. Buyer and Seller should meet personally to effect the exchange.

Port towns like Tondi, Korkai, Puhar and Muziri were developed by Pandiya kingdom.

Big cities like Poompuhar had two towns called 'Maruvurappakam' (inland town) and Pattinapakkam (Coastal town) had market and bazaars where many merchants met one another for the purpose of selling or buying different kinds of commodities and food stuff.

1. Roman and Greek traders frequented the ancient Tamil country and forged trade relationship with ancient Kings of Pandya, Chola and Chera dynasties. Cholas had a strong trading relationship with Chinese Song Dynasty. The cholas conquered the Sri Vijaya Empire of Indonesia and Malaysia to secure a sea trading route to China.
2. During the 16^th and 18^th centuries, India's overseas trade expanded due to trading with European companies. The discovery of new all-sea routes from Europe to India via Cape of Good Hope by Vascoda Gama had far-reaching impact on the civilised world. The arrival of Portuguese in India was followed by the advent of other European communities. India's maritime trade was a monopolised one over Europeans and at one stage the global trade share of India was 55 percent which is just 2 percent in 21^st century. The European merchants who came to India were not only individual merchants but also represented their respective governments. They gained a strong foothold in India's maritime trade by virtue of their strong naval power. In course of time, their commercial motives turned into territorial ambition like the East India Company which became the British Empire here.
3. Textiles and shipbuilding earned name and fame in the 17^th and 18^th centuries. Britishers gradually abolished Princely order in the Indian territories. Thus the demand for Indian goods declined during the British rule. Britishers put in place policies prohibiting the export of some of the popular goods like Indian textile goods, handicrafts, to Great Britain. Between early 1600and mid-19th century, the British East India company led establishment and expansion of foreign trade all over Asia. Although initial interest of the East India . Company was aimed at reaping profits, their single-minded focus was on establishing a trade, monopoly throughout Asia Pacific made them heralding agent of British Colonial Imperialism.

1. Roman and Greek traders frequented the ancient Tamil country and forged trade relationship with ancient Kings of Pandiya, Chola and Chera dynasties.
2. Cholas had a strong trading relationship with Chinese Song Dynasty.
3. The Cholas conquered the Sri Vijaya Empire of Indonesia and Malaysia to secure a sea trading route to China. During the 16th and 18th centuries, India's overseas trade expanded due to trading with European companies.
4. The discovery of new allsea routes from Europe to India via Cape of Good Hope by Vasco da Gama had far-reaching impact on the civilized world.
5. The arrival of Portuguese in India was followed by the advent of other European communities.
6. They gained a strong foothold in India's maritime trade by virtue of their strong naval power. 

Coastal Trade in Ancient Tamil Nadu:
1. Big cities like Poompuhar had the 'Maruvurappakam' (inland town) and 'Pattinapakkam' (coastal Town) had market and bazaars where many merchants met one another for the purpose of selling or buying different kinds of commodities and food stuff.
2. Port towns like Tondi, Korkai, Puhar and Muziri were always seen as busy with marts and markets with activities related to imports and exports.
3. In such a brisk trade, people of the coastal region, engaged themselves in coastal trade and developed their intercontinental trade contacts.
4. They were engaged in different kinds of fishing pearls, and conches and produced salts and built ships.
5. Boats like 'Padagu', 'Thimil', "Thoni', 'Ambu' 'Odampunai', etc... were used to cross rivers for domestic trade while Kalam, Marakalam, Vangam, Navai, etc.. were used for crossing oceans for foreign trade.

The barter system envisages mutual exchange of one's goods to other without the intervention of money as a medium of exchange. It imposes certain constraints in the smooth flow of trade as explained below.
Lack of Double Coincidence of Wants:
Unless two persons who have surplus have the demand for the goods possessed by each other, barter could not materialize. For instance 'A' is having a surplus of groundnut and 'B' is possessing rice in surplus. In this case A should be in need of rice possessed by B as the latter should desperately need groundnut possessed by A. If this "coincidence of wants" does not exist, Barter cannot take place.
Non - Existence of Common Measure of Value:
Barter system could not determine the value of commodities to be exchanged as they lacked commonly acceptable measures to evaluate each and every commodity. It was difficult to compare the values of all articles in the absence of an acceptable medium of exchange.
Lack of Direct Contact between Producer and Consumers:
It was not possible for buyers and sellers to meet face to face in many contexts for exchanging the commodities for commodities. This hindered the process of barter in all practical sense.
Lack of Surplus Stock:
Absence of surplus stock was one of the impediments in barter system. If the buyers and sellers do not have surplus then no barter was possible.