Political and ethical framework based on individual liberty via human rights and equal protection. Liberalism is a political philosophy or worldview founded on ideas of liberty and equality. Whereas classical liberalism emphasizes the role of liberty, social liberalism stresses the importance of equality.
Liberals espouse a wide array of views depending on their understanding of these principles, but generally they support ideas and programmes such as freedom of speech, freedom of the press, freedom of religion, free markets, civil rights, democratic societies, secular governments, gender equality, and international cooperation.
In a word: freedom.