An angstrom is a unit of measurement used to express very small distances, particularly in the fields of physics and chemistry. It is equal to one ten-billionth of a meter (10^-10 meters) and is often used to measure atomic and molecular dimensions, such as the size of atoms or the wavelengths of light. The symbol for angstrom is Å, named after the Swedish physicist Anders Jonas Ångström, who contributed significantly to the study of spectroscopy. This unit is especially useful in fields like nanotechnology and materials science, where understanding the scale of structures at the atomic level is crucial.