The pressure difference between the equator and the poles is primarily caused by the amount of heat in each area.
At the equator, the sun's rays hit more directly and consistently throughout the year, causing warmer temperatures and lower air pressure. Conversely, at the poles, the sun's rays hit at a more oblique angle, resulting in colder temperatures and higher air pressure. This temperature difference leads to variations in atmospheric pressure and is a key factor driving global wind patterns.
The rotation of the Earth on its axis (the Coriolis effect) influences wind patterns, but it does not directly cause the pressure difference itself.