Both Mango and Coconut fruits are drupe. They develop from monocarpellary ovary, but in both fruits edible part is different as shown below.

$\quad$ $\quad$ $\quad$ $\quad$$\quad$ Mango $\quad$ $\quad$ $\quad$ $\quad$ Coconut

Epicarp $\quad$ $\quad$ Skinny $\quad$ $\quad$ $\quad$ $\quad$ Skinny

Mesocarp $\quad$ $\quad$ Edible $\quad$ $\quad$ $\quad$ $\quad$ Fibrous

Endocarp $\quad$ $\quad$Hard & stony $\quad$ $\quad$ Hard & stony

Endosperm $\quad$ $\quad$ Not edible $\quad$ $\quad$ $\quad$ $\quad$ Edible