As the Baby Boomers — those born between 1946 and 1964 — retire in droves, and Generation X — born between 1965 and the late 1970s — is for the most part solidly entrenched in jobs and careers, it is likely the next employee you hire will be a millennial or a member of Generation Z. Millennials were born sometime between the early 1980s and 2000, and Generation Z was born in the 2000s.

Not all members of a generation are alike, but understanding the general characteristics...