I believe the answer is: Life Stages
Life stages refers to the period in people's life when we made one progression to another. In examining career stages, life stages is an important factors because it can be used to measure how far people had develop in their career.
For examples, adults with 2 children who made $35,000 a year would not be considered as advanced by today's standard, but a high school teenager who made that amount would definitely seen as advanced.