The Izod and Charpy test are both methods used to measure the impact strength of materials. While both tests assess the material's ability to withstand sudden forces, they differ in the way the sample is positioned and the direction of the applied force. The Izod test involves a vertically held specimen with a notched edge, while the Charpy test uses a horizontal specimen with the notch facing away from the impact point. Both tests are crucial in determining material durability for various applications.