Earth’s magnetic field

The Earth’s Magnetic Field

Earth's core contains liquid iron which moves around, due to the circular currents inside the core. Iron is magnetic so the liquid iron causes Earth to have a magnetic field. The Earth produces a magnetic field, just like a bar magnet, with the field lines being most concentrated at the poles.

The image you sent is a diagram showing Earth’s magnetic field. It compares Earth’s magnetic field to that of a bar magnet. Both have similar shapes and directions of their magnetic fields.

Compasses

Earth’s magnetic field is useful for navigation. The needle of a compass is a small magnet that can rotate. It turns around until its own magnetic field lines up with the Earth’s magnetic field. This means it always points North.

Image of a compass with the red needle facing North.

We know that opposite poles attract. The north pole of the compass is attracted to Earth’s magnetic South pole. Earth’s magnetic south pole is located near its geographic North pole. As a result, the North pole of a compass will always point towards Earth’s geographic North pole.

Summary:

The Earth's core contains liquid iron which moves around.
Iron is magnetic so the liquid iron causes Earth to have a magnetic field.