Lets get on to it!
we know that a wave is simply a disturbance in a certain surface or any kind of a field and this should be common to every wave even light. The problem comes with the property of light that it can travel without the necessity of any material medium i.e. vacuum.
So when light is travelling in a vacuum how can it be travelling as a disturbance i.e.wave when there is no substance to create a disturbance?(Or How can something i.e. light travel through nothing as a wave?)
I know for sure that vacuum cannot act as a field for disturbance to happen or take place on it because it is not a "thing" it is just the absence of "anything". Please answer in a understandable manner.