The term 'orange rind' refers to the outer layer of an orange, which is composed of the PEEL and ZEST. The PEEL is the tough, outermost layer of the orange, while the ZEST is the thin, colored layer of skin underneath the PEEL. Both the PEEL and ZEST are edible and can be used to add flavor to dishes. The PEEL can also be dried and used as a garnish or decoration. The ZEST is often used in baking and cooking to add a citrus flavor to dishes.