Css3 has added a new feature shadow to give shadow of elements. It supports two types of shadow:

• Text Shadow
• Box Shadow

Text Shadow:
You can use text shadow property to give text shadow effect. text-shadow property is used to give shadow effects to text elements. following are the examples:

h1{
text-shadow: 2px 2px;    
}

there are horizontal shadow and vertical shadow mentioned above.

h1 {
    text-shadow: 2px 2px 5px red;
}

You can add blur effect and color to text shadow in the third and fourth parameter. You can also add more than one shadow effect to a text element by using comma between two shadows like this:
 

h1 {
    text-shadow: 0 0 3px #FF0000, 0 0 5px #0000FF;
}

You can see the demo of text shadow here.

Box Shadow:
box-shadow property is used to give shadow effect to box elements like a container with a background or border.

div {
    box-shadow: 10px 10px;
}

It is same as text shadow parameter: horizontal and vertical.

div {
    box-shadow: 10px 10px 5px grey;
}

You can add color and blur effect to box shadow.

You can see the demo of box shadow here.