An airless bottle is a sophisticated dispensing system designed to protect its contents from exposure to air, light, and external contaminants. Unlike traditional bottles that rely on a simple pump and a direct air intake, airless systems use a mechanical, vacuum-based method to dispense product without ever letting air inside the container.
The defining feature is the barrier mechanism (often a piston or a flexible diaphragm) that rises as the product is dispensed, preventing any air from entering and replacing the used product.