It is the discharge of a catin at cathode .

Answer

**Step-by-Step Solution:**

1. **Understanding Electrolysis**: In electrolysis, an electric current is passed through an electrolyte, leading to the movement of ions. The electrolyte consists of cations (positively charged ions) and anions (negatively charged ions).

2. **Identifying Electrodes**: There are two electrodes in an electrolytic cell:
- **Anode**: The positive electrode where anions are discharged.
- **Cathode**: The negative electrode where cations are discharged.

3. **Cation Movement**: Cations, being positively charged, are attracted to the cathode (negative electrode). This is due to the opposite charges attracting each other.

4. **Discharge of Cations**: When cations reach the cathode, they gain electrons (reduction process) and are discharged. This process can lead to the formation of neutral atoms or molecules.

5. **Conclusion**: The discharge of a cation at the cathode is a fundamental process in electrolysis, where the cation is reduced by gaining electrons.

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