A core sample is a cylindrical section of material, often taken from the ground, that provides a snapshot of the layers of soil, rock, or sediment beneath the surface. This technique is commonly used in fields like geology, archaeology, and environmental science to study the composition and history of the Earth's crust. Core samples are collected using specialized drilling equipment, which extracts a vertical column of material. Researchers analyze these samples to understand geological formations, assess natural resources, or investigate past climate conditions. The information gained can be crucial for projects like oil exploration or archaeological digs.