One of history's most important economists, Ludwig von Mises, writes in In Human Action: A Treatise on Economics about two patterns of socialism:
"There are two patterns for the realization of socialism. The first pattern (we may call it the Lenin or the Russian pattern) is purely bureaucratic. All plants, shops, and farms are formally nationalized (verstaatlicht); they are departments of the government operated by civil servants. Every unit of the apparatus of production stands in the same relation to the superior central organization as does a local post office to the office of the postmaster general.
The second pattern (we may call it the Hindenburg or German pattern) nominally and seemingly preserves private ownership of the means of production and keeps the appearance of ordinary markets, prices, wages, and interest rates. There are, however, no longer entrepreneurs, but only shop managers (Betriebsführer in the terminology of the Nazi legislation). These shop managers are seemingly instrumental in the conduct of the enterprises entrusted to them; they buy and sell, hire and discharge workers and remunerate their services, contract debts and pay interest and amortization. But in all their activities they are bound to obey unconditionally the orders issued by the government's supreme office of production management. This office (The Reichswirtschaftsministerium in Nazi Germany) tells the shop managers what and how to produce, at what prices and from [p. 718] whom to buy, at what prices and to whom to sell. It assigns every worker to his job and fixes his wages. It decrees to whom and on what terms the capitalists must entrust their funds. Market exchange is merely a sham. All the wages, prices, and interest rates are fixed by the government; they are wages, prices, and interest rates in appearance only; in fact they are merely quantitative terms in the government's orders determining each citizen's job, income, consumption, and standard of living. The government directs all production activities. The shop managers are subject to the government, not the consumers' demand and the market's price structure. This is socialism under the outward guise of the terminology of capitalism. Some labels of the capitalistic market economy are retained, but they signify something entirely different from what they mean in the market economy.
It is necessary to point out this fact in order to prevent a confusion of socialism and interventionism."
Mises goes on to elaborate on this confusion:
"The system of interventionism or of the hampered market economy differs from the German pattern of socialism by the very fact that it is still a market economy....these are isolated acts of intervention. It is not the aim of the government to combine them into an integrated system which determines all prices, wages and interest rates and thus places full control of production and consumption into the hands of the authorities."
Politicians among the right and the left will often obfuscate policy debates by confusing or modifying these terms.