Both socialism and communism are essentially economic philosophies advocating public rather than private ownership, especially of the means of production, distribution and exchange of goods (i.e., making money) in a society. Both aim to fix the problems they see as created by a free-market capitalist system, including the exploitation of workers and a widening gulf between rich and poor.

But while socialism and communism share some basic similarities, there are also important differences between them.

Socialism emerged in response to the extreme economic and social changes caused by the Industrial Revolution, and particularly the struggles of workers. Many workers grew increasingly poor even as factory owners and other industrialists accrued massive wealth.

In the first half of the 19th century, early socialist thinkers like Henri de Saint-Simon, Robert Owen and Charles Fourier presented their own models for reorganizing society along the lines of cooperation and community, rather than the competition inherent in capitalism, where the free market controlled the supply and demand of goods.

Then came Karl Marx, the German political philosopher and economist who would become one of the most influential socialist thinkers in history. With his collaborator Friedrich Engels, Marx published The Communist Manifesto in 1848, which included a chapter criticizing those earlier socialist models as utterly unrealistic “utopian” dreams.

Marx argued that all history was a history of class struggles, and that the working class (or proletariat) would inevitably triumph over the capital class (bourgeoisie) and win control over the means of production, forever erasing all classes.

Communism, sometimes referred to as revolutionary socialism, also originated as a reaction to the Industrial Revolution, and came to be defined by Marx’s theories—taken to their extreme end. In fact, Marxists often refer to socialism as the first, necessary phase on the way from capitalism to communism. Marx and Engels themselves didn’t consistently or clearly differentiate communism from socialism, which helped ensure lasting confusion between the two terms.

Under communism, there is no such thing as private property. All property is communally owned, and each person receives a portion based on what they need. A strong central government—the state—controls all aspects of economic production, and provides citizens with their basic necessities, including food, housing, medical care and education.

By contrast, under socialism, individuals can still own property. But industrial production, or the chief means of generating wealth, is communally owned and managed by a democratically elected government.

Another key difference in socialism versus communism is the means of achieving them. In communism, a violent revolution in which the workers rise up against the middle and upper classes is seen as an inevitable part of achieving a pure communist state. Socialism is a less rigid, more flexible ideology. Its adherents seek change and reform, but often insist on making these changes through democratic processes within the existing social and political structure, not overthrowing that structure.

In his 1875 writing, Critique of the Gotha Program, Marx summarized the communist philosophy in this way: “From each according to his ability, to each according to his needs.” By contrast, socialism is based on the idea that people will be compensated based on their level of individual contribution to the economy.

Unlike in communism, a socialist economic system rewards individual effort and innovation. Social democracy, the most common form of modern socialism, focuses on achieving social reforms and redistribution of wealth through democratic processes, and can co-exist alongside a free-market capitalist economy.

Led by Vladimir Lenin, the Bolsheviks put Marxist theory into practice with the Russian Revolution of 1917, which led to the creation of the world’s first communist government. Communism existed in the Soviet Union until its fall in 1991.

Today, communism and socialism exist in China, Cuba, North Korea, Laos and Vietnam—although in reality, a purely communist state has never existed. Such countries can be classified as communist because in all of them, the central government controls all aspects of the economic and political system. But none of them have achieved the elimination of personal property, money or class systems that the communist ideology requires.

Likewise, no country in history has achieved a state of pure socialism. Even countries that are considered by some people to be socialist states, like Norway, Sweden and Denmark, have successful capitalist sectors and follow policies that are largely aligned with social democracy. Many European and Latin American countries have adopted socialist programs (such as free college tuition, universal health care and subsidized child care) and even elected socialist leaders, with varying levels of success.

In the United States, socialism has not historically enjoyed as much success as a political movement. Its peak came in 1912, when Socialist Party presidential candidate Eugene V. Debs won 6 percent of the vote. But at the same time, U.S. programs once considered socialist, such as Medicare and Social Security, have been integrated into American life.

Democratic socialism, a growing U.S. political movement in recent years, lands somewhere in between social democracy and communism. Like communists, democratic socialists believe workers should control the bulk of the means of production, and not be subjected to the will of the free market and the capitalist classes. But they believe their vision of socialism must be achieved through democratic processes, rather than revolution.