What is a 401(k)? Before you roll your eyes in a “Sheesh, is there anyone who doesn’t know the answer to that one?” way, consider this: in 2009, Fidelity Investments found that less than half (44%) of eligible workers in their 20s participated in their employer’s 401(k) plan. More than half of young employees did not set aside anything in their 401(k)s, whether by choice (they couldn’t afford to) or simply lack of understanding of their options. Like most investing vehicles, 401(k) plans can be confusing, with a multitude of investing choices, not to mention contribution rules and limitations. In this infographic, we give you the basics on 401(k) plans, in graphics.