Target date funds versus mutual funds
Target date funds are a specific type of mutual fund. Thousands of different mutual funds are available for investors, each with the purpose of pooling and investing money into a mix of different assets.
Mutual funds, including target date funds, can be actively or passively managed. Mutual funds that are passively managed simply track a financial index and therefore tend to have lower fees.
Target date funds versus index funds
Target date funds automatically rebalance over time to achieve a specific asset allocation on a target date, while index funds track stock market indexes such as the S&P 500 (^GSPC +0.04%).
Target date index funds are target date funds that invest only in index funds. Target date index funds typically have lower fees than other target date funds because they are passively managed. A fund manager of a target date index fund simply selects which indexes to track rather than actively managing investments in other types of assets.