What is the difference between 'Socialism' and a 'Social Democracy'?

[Joe Finkle]

It's essentially a matter of degree:

Note that what I refer to as moderate is moderate in world history, it's considered extreme in modern US political theory.

Extreme left:
In communism, the government completely controls the private sector and proportions work according to ability and benefits according to need (not very well, though, and it's inevitably a dictatorship to even try).

Moderate left:
Socialism is a mix of public and private sector. Vast industries are controlled by the government, but there is still room for free enterprise and people are not as directly controlled by the government.

Slight left:
In social democracy, the government represents the people, but also provides for them in terms of social benefits and management of certain industries, such as energy and health care, that function better under governmental control (in the opinion of that society). Sometimes there is room for private competition for the public programs, sometimes there is not.

Slight right:
In welfare capitalism, there are fewer areas deemed appropriate for the government to control and it is more likely that private companies would be allowed to compete with the government. The hallmark of welfare capitalism is the combination of the free market and social benefits and insurance.

Moderate right:
Lassez faire capitalism is the pure free market. It allows wild untempered swings and vast discrepancies in the distribution of wealth, essentially killing the middle class in favor of the upper and lower classes.

Extreme right:
Fascism is a type of dictatorship in which power is so concentrated that a single individual has all the power and can determine how everything should be run.

On both the extreme right and extreme left you have dictatorships. The differences at those ends aren't really that significant.