Social science refers collectively to academic disciplines that study society and the relationships among individuals within a society.
Stanford interview with Rom Harre - What is Social Science?
The humanities are usually defined as disciplines involved in the study of human culture. Culture can be defined in many ways. Culture can encompass the products and expressions of groups, such fine art, music, language and literature -- typically understood to be traditional areas of the humanities. However, culture can also be social behavior and norms, which sounds more like social science. Many people understand the differences between humanities and social science to be those of philosophy and approach.
This US animated video uses the metaphor of a university department to describe differences in social science fields.
This video from the UK puts social science in the perspective of how government and society is able to make changes and decide policy.