What is sorption ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Sorption**: Sorption is a general term that encompasses two processes: adsorption and absorption. It refers to the process by which one substance becomes attached to another.

2. **Understanding Adsorption**: Adsorption is a surface phenomenon where molecules adhere to the surface of a solid or liquid. For example, when ink particles are placed on cotton, some of the ink molecules stick to the surface of the cotton.

3. **Understanding Absorption**: Absorption, on the other hand, involves the incorporation of molecules into the bulk of a solid or liquid. In the same example, some ink molecules penetrate into the cotton fibers, becoming part of the material.

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