In general, we measure absolute prices in terms of dollars and relative prices in terms of units of some other good. However, many times we measure relative prices in terms of dollars also keeping in mind that the word dollar is being used to refer not to a piece of green paper but to a basket of goods. In microeconomics, the word prices always refer to relative prices. An ongoing rise in the average level of absolute prices. A cost is a foregone opportunity.
Comparative advantage is the ability to perform a given task at a lower cost.
In other words it is said to be more efficient. Everyone benefits when each person specializes in his area of comparative advantage and then engages in trade. Trade can help people specialize in different activities and helps them enjoy a variety of goods and services.