what exactly is wave (e.g. wifi, radio) and how does it travel in the physical world?

Question

I really can’t grasp the concept of waves. I can imagine it a bit for sound waves: a speaker has a surface that pushes air, and the moving air eventually pushes the membrane in our ears.

But I’m confused about wifi etc. What exactly is the thing that physically travels? Is it air or something else? Does it physically move in a wavy pattern?

Edit: thanks for all the answers! But damn I’m overwhelmed. It’s gonna take me days to read and fully understand the answers. But thanks!

In: 87

Answer 1

An easy way to think about it is that it’s light on a spectrum you can’t see with your eyes.