A command economy is an economic system in which the state controls all or most of the means of production and distribution of goods and services. The state determines what is produced, how it is produced, and who gets what is produced. This is in contrast to a market economy, in which these decisions are made by private individuals and businesses.
The former Soviet Union was a command economy. The state owned and operated all major industries, and it set prices and wages. This system led to a number of problems, including shortages of goods and services, low quality products, and a lack of innovation.