Images in plane mirrors are virtual because no light actually passes through them. Our brain forms a straight line along the path of reflection, leading to the virtual image.

For an object located at the Center of Curvature, C, the object will be inverted, the same size, and real. It's real because light passes through it.

For an object between the C and the Focal Point, F, the object will be inverted, larger, and real.

For an object outside of C, the object will be inverted, smaller, and real.