A virtual image is an image that is perceived to exist in a location where the light does not actually converge. It is formed by the apparent divergence of light rays when they are reflected or refracted by an optical system. Here are some key characteristics of virtual images:

1. Formation: Virtual images are formed when light rays appear to diverge from a point after reflecting or refracting through an optical system, such as a convex lens or a convex mirror. These light rays do not physically intersect or converge at a specific point.
2. Upright: Virtual images are typically upright, meaning they have the same orientation as the object being imaged. Unlike real images, there is no inversion of the top and bottom of the object in a virtual image.
3. Projection: Virtual images cannot be projected onto a screen or surface since the light rays do not physically converge. They can only be observed by looking into the optical system or by using an eyepiece.
4. Location: Virtual images are located on the same side of the optical system as the object. For example, when an object is placed in front of a convex lens, the virtual image appears on the same side as the object, but it is perceived as being farther away.
5. Interaction with Light: Virtual images are formed by the apparent divergence of light rays. These rays do not actually converge, but they appear to originate from a specific point when traced backward. This creates the perception of an image.

Examples of virtual images include the image seen in a plane mirror, the virtual image formed by a convex mirror, or the image seen through a magnifying glass.

Virtual images have practical applications in various fields. For example, virtual images formed by convex lenses are used in magnifying glasses and eyepieces of optical instruments like microscopes and telescopes. Plane mirrors also create virtual images used in mirrors for personal grooming or in security systems for surveillance purposes.