Convex mirrors always form virtual images regardless of object position and the image is formed behind the mirror in both cases I.e. at infinity and between infinity and the pole. The image is finished in both the cases.
Concave mirrors form a virtual image when the object is placed in between the Principal focus and the Pole and the image is formed behind the mirror. The virtual image is enlarged in this case. In all other object positions I.e. at infinity, beyond Center of curvature, at Center,between centre of curvature and principal focus and at principal focus, a real and an inverted image of the object is formed.
The ray diagrams for all the positions for the object in concave and convex mirrors are given below: