A magnifying glass uses a convex - converging - lens. The lens is moved close to an object - so the object is closer than the focal point. Rays of light from the object diverge as they pass through the lens. Construct in the image from tracing the light rays back to their apparent source gives an image that is magnified, upright, and virtual (because the light rays do not pass through the image/the rays do not converge).
, and the magnifying glass is moved towards and away from the object to obtain the best combination of sharpness and size.