Here's why:

* Reduction is a chemical reaction where a molecule gains electrons, leading to a decrease in its oxidation state.

* Oxidation is the opposite process, where a molecule loses electrons and its oxidation state increases.

* Redox reactions are reactions where both reduction and oxidation occur simultaneously.

Think of it this way:

* Reduction is like gaining a negative charge (electrons are negatively charged).

* Oxidation is like losing a negative charge.

Example:

In the reaction:

```

Fe³⁺ + e⁻ → Fe²⁺

```

Iron(III) (Fe³⁺) is reduced to iron(II) (Fe²⁺) by gaining an electron.