A wave is a disturbance that transfers energy through a medium or space without transferring matter. Waves carry energy from one point to another. There are two main types of mechanical waves: Transverse waves*: The particles of the medium oscillate perpendicular to the direction of wave propagation (e.g., waves on a string, electromagnetic waves). Longitudinal waves*: The particles of the medium oscillate parallel to the direction of wave propagation (e.g., sound waves). Key characteristics of waves include: Amplitude (A)*: The maximum displacement of a point of the medium from its equilibrium position. Wavelength (λ)*: The spatial period of the wave, the distance over which the wave's shape repeats. Frequency (f)*: The number of complete oscillations or cycles per unit time. Period (T)*: The time it takes for one complete oscillation (T = 1/f). Wave speed (v)*: The speed at which the wave propagates through the medium, given by v = λf.