O que é Share class, fee hurdle, crystallisation?

A share class is a category of a fund’s shares with its own terms: currency, fees, liquidity, minimum investment. A fee hurdle is a return, fixed or tied to a benchmark or a cash rate, that the fund must exceed before a performance fee is due. Crystallisation is the moment at which an accrued performance fee becomes payable to the manager and can no longer be reversed by later losses; the fund’s documents set its frequency.