Pressure changes refer to variations in the force exerted by air or fluids in a given area. These changes can occur due to factors like temperature, altitude, or weather conditions. For example, as you ascend a mountain, the air pressure decreases because there is less air above you. In meteorology, pressure changes are crucial for predicting weather patterns. High-pressure systems usually bring clear skies, while low-pressure systems can lead to clouds and precipitation. Understanding these shifts helps meteorologists forecast conditions and prepare for events like storms or heatwaves, impacting daily life and safety.