What is the difference between sinusoidal and non-sinusoidal waves?

a sinusdial wave can be represented in the form of sin function whereas we cannot express the non-sinusodial wave in terms of sine function.
Non-sinusoidal waveforms are waveforms that are not pure sine waves. They are usually derived from simple math functions. While a pure sine consists of a single frequency, non-sinusoidal waveforms can be described as containing multiple sine waves of different frequencies. These "component" sine waves will be whole number multiples of a fundamental or "lowest" frequency.