Real image refers to the image formed by the light from the object in front of the light passing through the optical device.
For example: images on camera negatives, images on eyes' retinas, images on movie screens and images on projector screens.
Virtual image refers to the image formed by the optical device after the light emitted by the object passes through the light.
For example: the words under a magnifying glass, the projection of water, the image in the mirror, a mirage.
The difference between real image and virtual image:
1. The imaging principle is different: the light emitted by an object passes through the optical device in front of the light to form an image. The image formed by the optical device after the light emitted by the object passes through the light.
2. The imaging direction is different: the real image is in front of the light and the virtual image is behind the light.
3. The imaging effect is different: the real image is inverted and the virtual image is upright. "Upright" or "inverted" is relative to the original.