Waves transfer energy from one point to another without physical transfer. There are two main types of waves: transverse waves where the vibration is perpendicular to the direction of travel, like water waves; and longitudinal waves where the vibration is parallel to the direction of travel, like sound waves. The key properties that describe a wave are its amplitude, wavelength, frequency, and period. The frequency is the number of waves that pass a point per second, while the period is the time for one full wave.
![WAVE ,[object Object],[object Object],[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)