As of 2015, Great Britain has a free market economy. It is the 13th freest economy in the word, based on the 2015 Index of Economic Freedom published by the Heritage Foundation. Based on GDP, Great Britain is also the sixth largest economy in the world.
A free market economy is one where the government has little control over transactions between buyers and sellers. The economy is primarily based on the country's supply and demand of goods and services. While transactions are based on a mutual agreement on price, there may be some government influence in the form of taxes or regulations.