Protective layers are barriers that shield objects or living beings from damage or harm. In nature, these layers can be found in various forms, such as the skin of animals, which protects against environmental factors, or the bark of trees, which guards against pests and diseases. In technology, protective layers are used in products like smartphones, where screens are covered with materials like Gorilla Glass to prevent scratches and cracks. Similarly, coatings on paint can protect surfaces from weathering and corrosion, extending the lifespan of the materials beneath.