The DIN setting is the amount of force required to release an alpine ski boot from the ski bindings. It is called the “DIN setting” because the Deutsches Institut für Normung, or, the German Institute of Standardization, issues the standards for Alpine ski bindings).
The DIN setting can be adjusted by turning a screw on the toe and heel piece of the bindings. DIN setting is based on the skier’s weight, height, boot length, age, and skiing ability/style. The lower the DIN, the less force is required to release the bindings.