The main difference between a veil and a mantilla is that a veil is a general term used to describe any head covering, while a mantilla specifically refers to a traditional lace veil from Spain. Veils can vary in length, style, and material, being attached to combs or headbands and made of lace or other fabrics. Mantillas are always made of delicate lace and worn draped over the head and shoulders and secured by ornate combs, symbolizing humility and respect within religious ceremonies.