Market mechanism is a term from economics

Economics

Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...

 referring to the use of money

Money

Money is any object or record that is generally accepted as payment for goods and services and repayment of debts in a given country or socio-economic context. The main functions of money are distinguished as: a medium of exchange; a unit of account; a store of value; and, occasionally in the past,...

 exchanged by buyers and sellers with an open and understood system of value and time trade offs to produce the best distribution of goods and services. The use of the market mechanism does not imply a free market

Free market

A free market is a competitive market where prices are determined by supply and demand. However, the term is also commonly used for markets in which economic intervention and regulation by the state is limited to tax collection, and enforcement of private ownership and contracts...

; there can be captive or controlled markets which seek to use supply and demand, or some other form of charging for scarcity, both in social situations and in engineering. This is a main term when it comes to marketing in economics...