Simply put, trade is the selling and buying of goods or services. In a trade, there is a buyer and a seller. The seller gains revenue while the buyer gains a good or service. Many things can be traded: resources, finished products, stocks, money, and a multitude of goods and services. Historically in societies that relied on agriculture, trade was as simple as exchanging a bundle of wheat for a piece of meat. Today, most trades are exchanges of money for a specific good or service. Countries trade with other countries to secure goods and resources they need. The benefit of trade is the advantage producers obtain by using specialization to increase overall output. It also gives consumers access to wider range of goods at potentially lower prices.
Globalization (the process of businesses, organizations, countries, and other agents engaging in international interactions, influence, or trade, integrating multiple economies), improved communication, and ease of transportation mean that virtually all countries engage in trade and interact with each other. Most nations have multiple trade connections with many other countries; thus, competition is a significant force in the international trade market.
The concept of comparative advantage is the reason why many countries participate in global trade, and it is also among the fundamental economic principles. Comparative advantage involves the opportunity cost of each party to produce a good. The idea can help parse out many of the foundational processes underlying international trade patterns and production decisions. Furthermore, criticisms of the comparative advantage theory help highlight some of the existing inequalities between countries and can provide a deeper understanding of the core issues surrounding international trade.