What is the point beneath Earth's surface where rock breaks under stress called?

The point beneath Earth's surface where rock breaks under stress is referred to as the focus, also known as the hypocenter. This is the location where an earthquake originates, and it is the first point of rupture that generates seismic waves. The focus lies directly beneath the epicenter, which is the point on the Earth's surface directly above the focus. Understanding the focus is crucial in seismology because it helps scientists determine the depth and intensity of an earthquake, affecting how the seismic waves travel and are felt on the surface. The correct recognition of these terms is central to comprehending how geological stress leads to seismic activity.