What is the term for where one air mass meets or pushes aside another?

The term that describes the situation where one air mass meets or pushes aside another is "front." In meteorology, a front represents a boundary between two different air masses that have distinct temperatures and humidity levels. These air masses can vary significantly in their characteristics, such as warm and cold air. When they converge, the resulting interactions can lead to various weather phenomena, including precipitation, changes in temperature, and shifts in wind patterns. Understanding fronts is crucial for predicting weather conditions, as they often indicate changes in the atmosphere. Other terms, such as "boundary," may refer to the general concept of separation but do not specifically encapsulate the dynamic interactions that occur at a front where air masses are involved.