The wave equation is a mathematical formula that describes how waves propagate through different mediums, such as air, water, or solids. It is commonly expressed in a second-order partial differential equation form, which relates the spatial and temporal changes of a wave. This equation is fundamental in various fields, including physics, engineering, and acoustics, as it helps predict wave behavior. In its simplest form, the wave equation can be written as ∂²u/∂t² = c²∂²u/∂x², where u represents the wave function, t is time, x is the spatial coordinate, and c is the wave speed. Solutions to the wave equation can describe different types of waves, such as sound waves, light waves, and water waves.