Cashew nuts are the dangly bottom bit on a fruit.
With 650,000 tonsper year, Nigeria is the biggest producer of cashews. Cashews are related to pistachios, mangoes and poison ivy. Each nut is in a kidney shaped face fruit which dangles from the so called cashew apple. That makes the cashew nut technically a seed.
Funnily enough; you could eat that accessory fruit straight from the tree, but you shouldn’t go for the fresh nut. The nut shell contains an oil or raisin, which is mildly toxic. If you try to peal the nut without roasting, boiling or steaming it first, the fluid can burn or irritate your skin. The liquid is not just a useless obstruction, it has many industrial uses, including friction linings, paints and resins.