An active fault refers to a geological or tectonic fault that is currently experiencing movement or may move in the future. Some synonyms for the term active fault include tectonic fault, active seismic fault, and seismic zone. Additionally, the term "fault line" is sometimes used interchangeably with "active fault," as it refers to the surface on which the fault causes movement. Other related phrases include "seismic activity," which describes the overall amount of movement and shaking caused by tectonic activity, and "focal depth," which refers to the depth beneath the earth's surface at which earthquakes occur. Regardless of the terminology used, understanding these concepts is critical to predicting and mitigating earthquakes and other tectonic events.