I've seen a few posts that posed a similar question. To be honest with all of you, I use to interchange "liberal" with "progressive" because the RW freep-jobs successfully tainted the word "liberal" (i.e. it's become a "dirty" word). So here are two offical definitions:
From Wiki:
Liberalism is an ideology, or current of political thought, which holds liberty as the primary political value.<1> Liberalism seeks a society characterized by freedom of thought for individuals, limitations on the power of government and religion, the rule of law, the free exchange of ideas, a free market economy that supports private enterprise, and a system of government that is transparent. This form of government favors liberal democracy with open and fair elections, where all citizens have equal rights by law, and an equal opportunity to succeed. Liberalism rejected many foundational assumptions which dominated most earlier theories of government, such as the divine right of kings, hereditary status, and established religion. Fundamental human rights that all liberals support include the right to life, liberty, and property. In many countries, modern liberalism differs from classical liberalism by asserting that government provision of some minimal level of material well-being takes priority over individual rights.
Now let's look at progressive also straight from Wiki:
Progressivism is a political philosophy whose adherents promote public public policies that they believe would lead to positive social change. As a broad characterization of political leanings, political progressivism mostly refers to social liberalism, social democracy, or green politics. Progressivism may also mean prefering moderate change, as opposed to minimal or maximum change. In this sense, it is contrasted with reactionary, conservative, as well as radical ideology. Progressive logic is the value logic that gives an underlying unity to this diversity of views.
Social Liberalism:
Social liberalism (new liberalism), a development of liberalism in the early 20th century, is a label used by progressive liberal parties in order to differentiate themselves from market liberal parties, especially when there are two or more liberal parties in a country. Additionally, it also means social progressivism, usually when contrasted with social conservatism.
Social liberalism is a political philosophy that emphasizes mutual collaboration through liberal institutions, rather than the threat and use of force, to solve political controversies. Social liberalism, as a branch of liberalism, contends that society must protect liberty and opportunity for all citizens, and advocates some restrictions on economic competition, such as anti-trust laws and price controls on wages ("minimum wage laws.") It also expects governments to provide a basic level of welfare, supported by taxation, intended to enable the best use of the talents of the population, to prevent revolution, or simply "for the public good."
Rejecting both radical capitalism and the revolutionary elements from the socialist school, modern liberalism emphasized positive liberty, seeking to enhance the freedoms of the poor and disadvantaged in society.
Social Democracy:
Social democracy is a political ideology that emerged in the late 19th and early 20th centuries from supporters of Marxism. Initially, social democratic parties included revolutionary socialists, such as Rosa Luxemburg and Vladimir Lenin alongside those who advocated a gradualist, evolutionary approach, such as Eduard Bernstein, Karl Kautsky and Jean Jaures. After World War I and the Russian Revolution, social democracy became exclusively associated with the non-revolutionary approach. Modern social democracy emphasises a program of gradual legislative reform of the capitalist system in order to make it more equitable and humane, while the theoretical end goal of building a socialist society is either completely forgotten or redefined in a pro-capitalist way.
The term social democracy can also refer to the particular kind of society that social democrats advocate. The Socialist International (SI) - the worldwide organisation of social democratic and democratic socialist parties - defines social democracy as an ideal form of representative democracy, that may solve the problems found in a liberal democracy. The SI emphasizes the following principles: Firstly, freedom - not only individual liberties, but also freedom from discrimination and freedom from dependence on either the owners of the means of production or the holders of abusive political power. Secondly, equality and social justice - not only before the law but also economic and socio-cultural equality as well, and equal opportunities for all including those with physical, mental, or social disabilities. Finally, solidarity - unity and a sense of compassion for the victims of injustice and inequality.
And Green Politics:
Green politics is a body of political ideas informed by environmentalism aimed at developing a sustainable society. It is considered by its advocates to be an alternative to both left and right views and parties, although adherents of both views tend to view Greens as "on the other side". Certainly it is true that Green parties advocate measures that appear to conventional politicians different from those grouped into labour and capital by economic interests.
Personally I lean towards socialism so I would identify more with "progressivism". What about you?
Edited to add a while bunch of stuff.
http://en.wikipedia.org/wiki/Progressivism http://en.wikipedia.org/wiki/Liberalhttp://en.wikipedia.org/wiki/Social_liberalismhttp://en.wikipedia.org/wiki/Social_democracyhttp://en.wikipedia.org/wiki/Green_politics