Distinguish between excretion and osmoregulation.

Explanation

### Step-by-Step Solution

1. **Definition of Excretion**:
- Excretion is the biological process through which organisms eliminate metabolic waste products from their bodies. These wastes primarily include nitrogenous compounds such as ammonia, urea, and uric acid, which are byproducts of protein metabolism.

2. **Purpose of Excretion**:
- The main purpose of excretion is to remove harmful substances and maintain the internal environment of the body by eliminating toxic waste products that could disrupt cellular functions.

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