Socialism is a broad term used to describe various forms of socio-economic organisation that involve the collective ownership of property in some form or another.

The tendency of the socialist you ask would greatly alter the meanings you're told. Whereas an orthodox Marxist would argue that socialism and communism are synonymous, a Leninist would argue that that socialism is the transitional state that would exist between capitalism and stateless communism.

You're also going to hear lots of folk misusing the terms. In mainstream discourse the term socialism is often used to describe government intervention into the market and a large welfare state. Most commentators believe that the Soviet Union was an example of communism and that communists want the state to take over the role of private corporations.

Of course these mainstream definitions aren't accurate but due to how common these misconceptions are you'll often hear them. Once again socialism means the collective ownership of the means of production. Communism entails a classless and stateless society where the means of production are collectively owned and all individuals are free to access the articles of consumption.

All communists are socialists but not all socialists are communists.