(CNN)Here's a look at five generations of Americans in the 20th century: the "Greatest Generation" (or GI Generation), the "Silent Generation," baby boomers, Generation X and millennials. In order to examine economic trends and social changes over time, demographers compare groupings of people bracketed by birth year. There are sometimes variations in the birth year that begins or ends a generation, depending on the source. The groupings below are based on studies by the Census, Pew Research and demographers Neil Howe and William Strauss.
Born in 1924 or earlier.
Born 1925-1945 (Sometimes listed as 1925-1942).
Born 1946-1964 (Sometimes listed as 1943-1964)
Born 1965-1980 (Sometimes listed as 1965-1979)
Born 1981-1997 (Sometimes listed as 1980-2000; the range of birth years for millennials may be updated as further demography studies about this generation are conducted, according to Pew Research).
The next generation of children and teens younger than millennials has not been formally named by demographers yet.