What is defined as the part of the nail not connected to skin at the tip?

The correct answer describes the free edge of the nail, which is the portion that extends beyond the nail bed and is not attached to the skin. This free edge is typically seen at the tip of both fingernails and toenails and serves both functional and aesthetic purposes. It protects the underlying fleshy tip of the finger and contributes to the overall appearance of the nail.

This area is easily visible and distinguishes itself as the part of the nail where growth can be monitored, and it often requires trimming to maintain nail hygiene and appearance. By defining the free edge as part of the nail that is not connected to the skin, the answer correctly highlights a key characteristic of the nail's anatomy.

In contrast, the other options do not accurately capture this concept. The sides of the finger do not refer specifically to the free edge, nor does the aspect of being found only on toes relate to the general characteristics of the free edge in both types of nails. The nail base is not the part that extends beyond the fingertip, making it irrelevant to the free edge's definition.