Why are nails so hard?

Explanation

### Step-by-Step Solution:

1. **Understanding the Composition of Nails**:
- Nails are primarily composed of a protein called keratin. Keratin is known for its hardness and is a key structural material in various parts of the body, including hair and skin.

2. **Growth Process of Nails**:
- Nails grow from the base, specifically from an area located beneath the cuticle. This area is known as the nail matrix, where new nail cells are produced.

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