Deforming a plane

How do I deform the plane as the fellow did in the following video, at minute 3:49 to 3:58, Thanks

I don’t think the general forums is where you would ask for help. Next time, you should probably try Support -> Modeling. And to answer your question, it looks like he in the video subdivided the plane with W, adjusted the number of cuts with the slider on the left, activated proportional editing with O, and dragged several points upwards to create a bumpy terrain.

Thanks so much, that was it, will try to post in the proper area next time. Thanks again.