Incident wave definition

incident wave is an incoming wave

if one is far enough from any wave source (water, sound, EM), the incoming waves look like plane waves

If i use this wave in my design, what that meaning? I wanted to provide magnetic field on my design? How can i do this?

There's no thing like a "magnetic wave". Electromagnetic waves involve coupled time variant electric and magnetic fields.

maybe you should explain a little more about what you want to do