What does dustproof and waterproof level IP68 mean?

IPXX is a protective security level in the industry. IP is the abbreviation of Ingress Protection Rating. It refers to the protection capabilities of a liquid and solid particles in the interface. The two-digit number after IP67, the first number is the solid-state protection level (its range is 0-6); the second number is the liquid protection level (its range is 0-8). The larger the number, the stronger the protection ability.