Take a look at your workforce. Chances are high that it's generationally diverse, with Boomers, Generation Xers, and Millennials working at every level. That last cohort – Millennials, Gen Y, Generation Next, etc. – has been the subject of boundless research and discussion in the past 15 years.
Often when older generations discuss younger ones, the context is negative and may include words like entitled, unmotivated, and tough to manage. As a leader, when your young Gen Y employees aren't meeting your expectations, it's easy to tag the issue as a "generational defect."