Cashew trees are attractive trees with large leaves and pretty, pink flowers. (See the photo above.)
Cashews, as you know them, are nuts. But the cashew nut is not the only fruit of the cashew trees. Or rather, the cashew nut is only a part of the cashew fruit.
The other part is called the cashew apple. (Although pear would suit it much better.) And if I wanted to be super accurate then I'd have to point out that the cashew apple is actually the swollen stem of the fruit.
In the picture below are two ripe cashew apples and on the right, you can see some young fruits where the stem has not swollen yet.