A **professional driver** is a person whose **main work activity** is driving vehicles intended for the **transport of people or goods**. This means that their daily job involves operating vehicles such as buses, trucks, or taxis, among others, to carry out the transportation of passengers or goods.

- **Driver**: This is anyone who operates a vehicle, whether it be a car, a motorcycle, or any other type of transport. However, not all drivers are considered professionals, as not all do it as their main work activity.

- **Regular driver**: This is someone who frequently operates a vehicle, but not necessarily as their main job. It could be a person who often uses a family member's or friend's car, but they are not considered professional unless their main job is driving.

In summary, to be considered a professional driver, it is necessary that driving is the **main activity of their job**, focusing on the transport of people or goods.