What is the zone between contrasting air masses called?

The zone between contrasting air masses is called a front. In meteorology, a front is defined as the boundary that separates two different air masses, which can vary in temperature, humidity, and density. This zone is critical because it is often where weather changes occur; for example, you can experience shifts in wind, precipitation, and cloud formation when weather systems interact at a front.

While warm fronts and cold fronts are specific types of fronts characterized by the movement of warm air over cold air or cold air replacing warm air, respectively, the term "front" encompasses all types of boundaries between contrasting air masses. This includes not only warm and cold fronts but also stationary fronts and occluded fronts, each with distinct characteristics and weather implications.

Understanding the general term "front" helps in grasping how different types of fronts function and the general dynamics of weather patterns as they develop in the atmosphere.