The sound waves are longitudinal waves. The electromagnetic waves are?

Hint: We know that there are different types of waves involved in our day-to-day observations. We need to understand the difference between the types of waves to understand and categorize the different waves into waveforms and study them properly.

Complete step by step solution:
We know that there are mainly two types of mechanical waves, which we come across in our daily experiences. The mechanical waves are the transverse waves and the longitudinal waves. Let us discuss each of them to understand the differences between them.
1.Transverse waves: These waves are those which travel perpendicular to the oscillation of the particles which cause the wave. The particles oscillate perpendicular to the direction of the wave as shown below.

The transverse waves do require a medium to propagate. The particle oscillations set the waves. Electromagnetic waves are a type of transverse wave, which doesn’t require a medium.

The oscillating charge produces the magnetic field and electric field in a mutually perpendicular direction, which is perpendicular to the wave propagation also. The electromagnetic waves are three-dimensional examples of transverse waves.
2.Longitudinal waves: These waves are those in which the particle oscillation is in the direction as that of the wave propagation as shown below.

The longitudinal wave propagation requires a particle medium for the wave movement. It propagates by creating areas of high pressure (compressions) and areas of lower pressures (rarefactions). This is not possible without a medium. The sound waves are examples of longitudinal waves.
We understand that electromagnetic waves are transverse waves as the sound waves are longitudinal.
This is the required solution.

Note: The electromagnetic waves are transverse waves, but they are mostly regarded as a special and different waveform due to its lack of interaction with particles and the remaining unsolved mysteries in the electromagnetic theories that explain them.