Socio-economic mobility in the United States refers to the movement of Americans from one social class or economic level to another, often by changing jobs or marrying. This "vertical" mobility can be the change in socioeconomic status between parents and children ("inter-generational"); or over the course of a lifetime ("intra-generational"). It typically refers to "relative mobility," the chance that an American's income/status will rise or fall compared to others in another income/status group but can also be "absolute," whether (and by how much) living standards in America have increased.