The costs of loading (“in”) and discharging (“out”) are free to the shipowners i. e. the charterers will pay the loading costs and the consignees (or charterers) will pay the discharge costs.
In return, charterers are usually entitled to a reduced freight rate. “Free in and out” is the usual agreement in bulk shipping charter parties, since bulk charterers are generally in the best position to control loading and discharge costs, especially where also operate the bulk terminals.