Voluntary exchange is the act of buyer

Buyer

When someone gets characterised by their role as buyer of certain assets, the term "buyer" gets new meaning:A "buyer" or merchandiser is a person who purchases finished goods, typically for resale, for a firm, government, or organization...

s and sellers freely and willingly engaging in market

Market

A market is one of many varieties of systems, institutions, procedures, social relations and infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering their goods or services in exchange for money from buyers...

 transactions. Moreover, transactions are made in such a way that both the buyer and the seller are better off

Utility

In economics, utility is a measure of customer satisfaction, referring to the total satisfaction received by a consumer from consuming a good or service....

after the exchange than before it occurred. Economists believe that voluntary exchanges are more conducive to economic efficiency than exchanges mandated by governments.

According to professor Arnold Kling, in certain cases forbidding a voluntary exchange can benefit somebody at the expense of others.