One fund can have a dozen classes: institutional with a low fee and a high minimum, retail with a higher fee that includes distribution costs, hedged and unhedged currency versions, and accumulating and distributing versions.
All classes own a slice of the same assets, so gross performance is identical. Net performance differs only by the class's own charges and hedging results, which can amount to a full percentage point a year between the cheapest and most expensive class of the same fund.
Check which class a quoted performance figure refers to before comparing funds. The clean institutional class is often what appears in marketing while the accessible class carries a materially higher total-expense-ratio.
Related: distributing-share-class, total-expense-ratio, twelve-b-one-fee, mutual-fund, management-fee