I want to explain what I understood of definition of the two things.
Projection plane: The general processing steps for modeling and converting a world coordinate description of a scene to device coordinates, we need projection plane.
Projective plane: We know that $P^2$ is all $\mathbb R^2$ points and point at infinity.In projection plane any point exists in $(∞,∞)$ if we want to represents it then we need projective plane.
For instance, a point in Cartesian $(1, 2)$ becomes $(1, 2, 1)$ in Homogeneous. If a point, $(1, 2)$, moves toward infinity, it becomes $(∞,∞)$ in Cartesian coordinates. And it becomes $(1, 2, 0)$ in Homogeneous coordinates, because of $(1/0, 2/0) ≈ (∞,∞).$ Notice that we can express the point at infinity without using $"∞".$
My question is what's difference between Projection plane and Projective plane?