What do we study in electromagnetism ?

Explanation

### Step-by-Step Solution:

1. **Definition of Electromagnetism**: Electromagnetism is a branch of physics that studies the interactions between electric charges and magnetic fields. It encompasses both stationary and moving charges.

2. **Charged Particles**: In electromagnetism, we examine the behavior of charged particles, such as electrons. For instance, when an electron is at rest, it creates an electric field around it.

3. **Effect of Motion**: When the electron starts moving, it generates a magnetic field in addition to the electric field. The study focuses on how these fields interact with other charges and magnetic materials.

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