A simple comprehension of waves can be seen when you drop a small pebble into a still water pond, the water surface is disturbed, it spreads in outwards circles. It feels like there is a movement outward from the point of disturbance. Actually, the water mass does not flow outward with the circle, but a moving disturbance occurs. These patterns move without the actual physical transmission or flow of matter as a whole and are called waves.

What is a wave:

Wave definition:  Waves are the regular and organised propagation of turbulence from place to place. This can basically be described as an obstacle in passing the medium from one place to another.

Example:  Waves are everywhere. Some forms of wave could be found in a surprising variety of practical day to day applications, from oceans to acoustic science. Simply put, waves are an ongoing disturbance. Sea waves travel thousands of kilometres in the water. Seismic waves hit the earth, reflecting back from the earth’s innermost part and returning to the surface. 

Classification of waves:

On the basis of medium –

• Mechanical waves –  Mechanical waves require a medium that can move, such as sound waves or water waves. 
• Electromagnetic waves – electromagnetic waves do not require a medium and can be propagated through a vacuum, e.g., Radio waves, microwaves, visible light, and x rays.

On the basis of shape – 

• Longitudinal waves – Longitudinal waves are waves composed of periodic disturbances or vibrations that arise withinside the identical route because the wave propagates. Longitudinal waves are composed of “compression” and “rarefactions” wherein debris are bundled and unfolded out respectively. Sound waves are an instance of longitudinal waves. 
• Transverse waves – When you think of a wave, you probably think of a transverse wave. It looks like a wavy line with peaks and valleys that we call ridges and valleys. Here, the particles traverse perpendicular to the wave’s line of propagation e.g., an electromagnetic wave. The high part of this curve is called the crest. The lower part is called the trough. The part actually shows the maximum change because directions like up and down don’t always make sense for the waves.

Different parameters of Waves:

• Amplitude – Amplitude, in physics, is the most displacement or distance moved through a factor on a vibrating body. It is identical to one-1/2 of the duration of the vibration path. The amplitude of a pendulum is for that reason one-1/2 of the gap that the bob traverses in transferring from one facet to the other. Waves are generated through vibrating sources, their amplitude being proportional to the amplitude of the source. 

• Wavelength – Wavelength can also be measured in continuous valleys or between any two equivalent points on the wave. Wavelength is a characteristic of a wave that is the distance between the same points between two consecutive waves. The distance between one peak (or valley) of a wave and the next is the wavelength of the wave. In the equation, the wavelength is given by the Greek letter lambda (λ). 

• Frequency – Frequency is defined as the number of recurring events per second. Therefore, for a sine wave, we define the frequency as the number of cycles completed per second. Frequency is expressed in ‘f’ or ‘ν’, calculated in hertz or Hz and measured in cycles per second (hertz). Waves with a frequency of 40 Hz go through a 40-wave cycle per second.

• Time period – To find the frequency, just count the frequency per second. Another way to count is to find out how long it takes to complete a cycle and then calculate the number you can get per second. The time of complete vibration is called the period (T) and is measured in seconds.’

Conclusion:           

In conclusion, we have considered the transverse and longitudinal waves of water and  air and some of their properties. All waves are associated with oscillations and periodic motions that repeat over time. But waves aren’t the only ones exhibiting this behaviour.