Why do air masses move north and south?

The most important principle by which air masses move is movement in the direction of pressure drop and vice versa. For example, somewhere there was an area of increased pressure, which was formed as a result of the heating of the surface by the Sun, heavy rain passed there and a zone of reduced pressure was immediately formed, and therefore the air mass moves there, but there is no such principle that it is to the north or exactly to south. Also, the movement of air masses is affected by the rotation of the Earth around its axis.