Single face plane

[micheus]

How do you create a single faced plane? Like for making a terrain. I do not need a bottom face.

Depending on what you are going to do with this plane, it's also possible to extract a single face of a cube, for instance.
This will create an object with only four vertices and two faces (up and down). In this case usually we may need to set the boundaries edges to hard to not have problem smoothing it.