How Formation of shadows formed.?

A shadow is a dark space (shade) formed behind an opaque object , when it blocks light from any source of light.

a shadow is formed when an opaque is present infront of a source of light

a shadow is formed when an opaque object is in front of a source of light
 

Sometimes objects can block light which means that no light is able to pass through that object. An object from which no light can pass through is called?an opaque object. The easiest example is our body. Stand in the way of a beam of a light from a small torch. Ask someone to stand behind you and spot the beam of light. The person behind you will see no light since your body did not allow it to pass. Whenever light is not able to go through an object, it creates a dark area around the object. This patch where the light can not reach is called a shadow. Opaque objects create clear dark shadows.

PICTURE:

Formation of shadow
If an opaque object comes in the way of a light source, light does not pass through it. As a result, the light does not reach a wall or any other surface on the other side of the object. That part remain dark. This dark part is called the 'shadow of the object'.

A shadow is actually just a space or region, where there is no light since an opaque object is blocking light rays. The position and intensity of the source of light affects the properties of the type of shadow that is formed. ... If it is a point source of light, then it forms a simple shadow called an umbra.