What typically identifies a gel nail system?

A gel nail system is specifically characterized by its requirement for a UV or LED light to cure and harden the product. The chemical composition of gel formulations involves photoinitiators that react to UV or LED light, causing the gel to polymerize and establish a hard, durable finish. This curing process is essential for achieving the desired strength and longevity of the gel nails, which distinguishes them from other types of nail systems.

In contrast, air-drying products do not undergo a curing process involving light, which places them outside the definition of gel systems. Gel nails are also available in a wide variety of colors, not limited to dark shades, and they do require specialized equipment for curing, contradicting the notion that no special equipment is necessary. Therefore, the defining feature of a gel nail system is indeed its reliance on UV or LED light for proper curing, confirming the accuracy of the answer.