The exact point underground where pressure is released, leading to an earthquake, is called the "hypocenter" or "focus." This is the location within the Earth's crust where strain energy stored in the rock is first released, causing the fault to rupture and generating seismic waves. The hypocenter lies directly beneath the epicenter, which is the point on the Earth's surface directly above it. The rupture begins at the hypocenter and then propagates along the fault line, releasing energy that causes the shaking felt during an earthquake. The depth of the hypocenter is also known as the focal depth and varies depending on the earthquake.