Final answer:
Real images are formed by converging light rays and can be projected onto a screen, while virtual images are formed by diverging rays and cannot be directly projected but can be seen and photographed. Lenses or mirrors can be used to transform a virtual image into a real one to allow projection.
Step-by-step explanation:
The main difference between real and virtual images is their formation: a real image is formed when light rays converge and can be projected onto a screen, while a virtual image is formed when light rays diverge but appear to come from a common point when traced backward. To determine if an image is real or virtual, you can check if it can be projected onto a screen—this indicates a real image. Conversely, virtual images cannot be projected since the light does not actually pass through the image location.
Virtual images can be seen because we can perceive light rays as they appear to come from a location behind the lens or mirror. While you cannot project a virtual image onto a screen directly, using additional lenses or mirrors can convert the virtual image into a real one, which can be projected. It is also possible to photograph a virtual image, as a camera can capture the light from the virtual image much like it captures light from real objects.
It is not necessary for a real image to be projected onto a screen for it to exist; it only needs to be possible to project it for the image to be classified as real.