Abstract : The goal of the review is to describe recent advances in the study of shock waves and to emphasize the change in viewpoint that has been brought about by the appearance of in-material gages of high time resolution. It emphasizes the concept of unsteady waves and discusses the analytical procedures that have been developed to handle experimental data from unsteady waves in solid materials. The following topics are discussed: Shock waves and their production in the laboratory; Constitutive relations; Stress wave propagation; Instrumentation and measurement techniques; Effects of shock waves in solids; Comparison of static and dynamic results.