Interfaces in Object Oriented Programming Languages. An interface is a programming structure/syntax that allows the computer to enforce certain properties on an object (class). For example, say we have a car class and a scooter class and a truck class. Each of these three classes should have a start_engine() action.
The epidermis is the very outer layer of the skin that provides protection from bacteria (thanks to it's pH level), becoming overloaded with water (it's waterproof) and from heat loss. It has four of five distinct layers to achieve this.
The epidermis is the epithelial tissue layer of skin. Hair follicles, sebaceous glands, and sweat glands are epithelial invaginations from the epidermis. The dermis is the connective tissue layer of skin. Embedded within the dermis are hair follicles and sweat glands as well as blood vessels and sensory nerve endings.