Fund fees refer to the expenses incurred by an investor when they purchase shares or units in a mutual fund, exchange-traded fund (ETF), or other similar pooled investment vehicles. These fees are charged for managing and operating the fund, which includes costs such as management fees, distribution fees, and other expenses related to running the fund. Fund fees can have a significant impact on an investor's returns over time, so it is important for investors to understand these fees and consider them when making investment decisions.